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General Forestry => Chainsaws => Topic started by: XP_Slinger on December 28, 2015, 08:16:01 AM

Title: 372XP X-Torq Modding
Post by: XP_Slinger on December 28, 2015, 08:16:01 AM
Hey All,

    I will be tearing into my X-Torq 372XP this weekend and I am looking for the safe squish range for this model saw.  Can I go by the old standard of .020 or more being safe?  I just did a muffler Mod and base gasket delete on my 346XP NE and the increase in performance was well worth the effort, so naturally I MUST tinker with my other saws too.  Are there any other tweaks I can do while I have the 72 torn down? Thanks for any information offered.

Josh
Title: Re: 372XP X-Torq Modding
Post by: 49er on December 28, 2015, 09:58:52 AM
I have a 365xt that I have tweaked some. My squish is very close to .020. I used Locktite gasket maker 518. This brought the compression up to 195.
   
Spike60 has a thread covering some basic mods. He described taking a little off the piston skirt to increase intake duration. Ya might do a search.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on December 28, 2015, 10:44:44 AM
 I am using 3-Bond crankcase sealant.  I will do a better search for X-Torq mods.  Thanks for the reply
Title: Re: 372XP X-Torq Modding
Post by: ehp on December 29, 2015, 09:32:39 PM
there are lots of mods you can do to the XT's , squish I would not go any tighter than .020, I would sooner see .022 . Yep lots of guys go tighter but not me . I run modded XT's everyday logging and have zero problems other than fuel line is junk so switch it out to tygon and no more problems . Remember when you pull the gasket out your also lowering the ext. and transfers so this will also lower your peak torque rpm , yes lowering the cylinder will increase torque but instead of say 9600 rpms you will be closer to 9200 rpms of peak torque if motor was put on a dyno . I myself donot pull the base gasket out , reason it if saw is used real hard everyday 8 hours a day the silicon will at some point fail and cause a air leak as at some point you will get the cylinder temperature up to high and it will fail , doesnot matter what you use , I have seen them all fail . I cut the base of the cylinder and use the gasket
Title: Re: 372XP X-Torq Modding
Post by: 49er on December 29, 2015, 11:00:05 PM
Ehp, do you then raise the exhaust and transfer ports back to the stock location to get the rpm's back? I got a little south bend lathe but I have never cut a base yet.
Title: Re: 372XP X-Torq Modding
Post by: ehp on December 30, 2015, 07:40:02 AM
No I raise them a lot more than stock, my motors peak torque is at 12,500 to 12,700 rpms and will pull a 36 inch bar setup in hardwood pretty good . I normally run 24 to 28 inch .
Title: Re: 372XP X-Torq Modding
Post by: Al_Smith on December 30, 2015, 09:10:28 AM
I've never reworked any Husqvarna but I have several Stihls and a couple McCullochs .

I'm with Ed on this one. I like a gasket and about 22 thou piston/head deck clearance .Raised exhaust to maybe 96 degree opening and upwards of 27-30 degree blow down .It jacks about 2000 rpm to them and doesn't kill the torque .

Fact I have the exact same displacement Stihl that will pull a 32" all day and never run hot and never fail to start .

Keep in mind there's much more than numbers   to reworking an engine such as port shapes etc .We might differ in how that's done but end results have  more creedance that opinions  .End results are what really count the rest is just conversation ;D
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on December 30, 2015, 10:47:49 AM
Thanks for all the information guys.  I am still learning about porting and all that and I am not quite ready to get a degree wheel and start grinding.  I am a firewood/hobby guy and since my livelihood does not rely on my chainsaws RPMs I am ok with peak torque dropping by 400ish, my 346 still felt stronger after deleting the gasket despite the drop in peak torque RPMs.  I really appreciate the confirmation of the .020 limit to squish.  My experience with the metal on metal gasket maker is the opposite in that I have never seen the correct compound fail.  Thanks again for all the info. Once my knowledge is higher I will port it the right way, but for now I'll keep going the "Farmer Jones" route.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on December 30, 2015, 02:00:08 PM
On those xtorqs, the squish band is usually nice right from the factory & a base gasket delete gets you right to the .020 range. Of course you have to check the squish...every time! I wouldn't push it closer than .020" either. A muffler mod does help as well in moderation. A common sense thing. I have the choice to either cut the cylinders or not because I have the capability, but on those I choose not to. I do have and know of quite a few Three Bond Builds out there now on a variety of saws in a variety of situations, for several years. Haven't seen a failure yet and on my project saws I've torn down, the Three Bonded cylinders were glued to the cases to where it took a fair amount of effort to break them free. And interestingly enough the only X-torq I have seen with a gasket issue was one with an OEM base gasket. One thing I've been persuaded to do is pull the transfer caps..carefully not to tear and ruin the rubber gaskets & re glue them on with 1184. So I'm not afraid to suggest that Three Bond approach where 2 or three years ago I was hesitant.

I'm not implying that cutting the cylinder isn't a good approach, its been "THE" correct approach for years. My bet is MOST of the true performance saws that were truly professionally (good builders) build have that approach. And those who do it well have latitude for further tuning/porting option those limited to a base gasket delete don't have simply because of geometry. And those who have developed a process and track record with that build process obviously need to continue doing exactly that vs. throw variables into the mix. Right now the process I've adopted and further developed on certain saw builds is using Three Bond adhesives. Not going to change at this point until I see a tangible reason to do so and so far its been exactly the opposite, I'm seeing more reasons and uses for those products to this point. Takes a lot of risk and cost out of the equation. Especially for those who either don't have a machining option or don't want to fork out the additional coin on hobby or project saws. And now with saws that have lived the 24-7 logging world under my belt I'm more convinced than ever that its a valid approach. If any one has been paying attention, I'm a hard sell, a sceptic, but still have that engineering back ground that needs data. Having said that, I not a fan of some of the other "grey" goo gasket products out there. Not because I've see them actually fail because I haven't. It's because when I was doing the research and testing, pulling the cylinders wasn't any where near as difficult as with the Three bond 1194. They pulled right off making me nervous about those products. They still sealed...just a perception thing.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on December 30, 2015, 02:31:21 PM
Weimedog,

    Your experience is certainly appreciated with regard to Three Bond 1194.  It's what I've been using and hasn't let me down.  Thanks for the squish info, and I always check squish prior to disassembly.  Pretty easy to do the math ahead of time instead of deleting the gasket and reassembling only to discover squish is too tight. 

Josh
Title: Re: 372XP X-Torq Modding
Post by: weimedog on December 30, 2015, 02:44:07 PM
Thank you for the feed back...and I'm always open to new data, not a pride thing with me.

To me the real test is going to be a series of 562's with Three Bond Builds over this year. They do scare me and will certainly be the test that makes or breaks the concept as a general vs. specific solution.

I don't understand the engineering behind the 562. They obviously wanted to get things hot in the front side where the transfer ports are because the muffler design helps hold the heat right there. I guess theoretically the fresh charge from the transfer helps cool therefor picking up heat in the charge before entering the combustion chamber....I don't know. Also there is a clearance issue potentially where the transfer caps & screws may actually hit the cases before the cylinder seats without a OEM base gasket...those gaskets seem to typically be in the .028-.030" range. I have to wonder if any of those saws out there have leaks in the cylinder/case junction because of those caps interfering with the cases. Nothing a die grinder can't fix, but not something you would be looking for. Either way.... that area has to be a worst case for a sealer...so I'm going to test and document that test over time to either verify or question goo gasket concepts... Time will tell.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on December 30, 2015, 04:57:27 PM
Can't wait to see you results!  I've been toying with the notion of picking up a 562 and would very interested in what you discover.  I am just getting into really learning about porting/modding these little 2 strokes and it's adictive. 
Title: Re: 372XP X-Torq Modding
Post by: old 030 on December 31, 2015, 07:24:10 AM
there's a pretty good vid on you tube of the j-red version 2166, they removed the base gasket and trimmed .050 off the intake skirt of the piston, can't remember if they worked over the transfer covers or not, looked to run real strong, the 2166 is shown being run along other j-red and huskys of similar cc or very close to....about a ten minute vid, i found it searching info on the 2166..... ;)
Title: Re: 372XP X-Torq Modding
Post by: ehp on December 31, 2015, 07:37:09 AM
My 562 cuts almost the same as a stock 395 both saws running the same 28 inch bar and chain in red oak and out cut a stock 372 XT bad , videos are on my youtube  channel and this 562 has cut a pile of timber , they can be made to run very hard
Title: Re: 372XP X-Torq Modding
Post by: CR888 on December 31, 2015, 09:25:49 AM
Do you think, a 555 can be built to run as well as a 562 ehp? I know the 555 is basically a detuned 562 without crank stuffers, smaller transfers, maybe different ignition advance etc. But do you think you could end up with the same result after some effort?
Title: Re: 372XP X-Torq Modding
Post by: weimedog on December 31, 2015, 12:31:51 PM
Quote from: CR888 on December 31, 2015, 09:25:49 AM
Do you think, a 555 can be built to run as well as a 562 ehp? I know the 555 is basically a detuned 562 without crank stuffers, smaller transfers, maybe different ignition advance etc. But do you think you could end up with the same result after some effort?

Maybe not a 562ehp! Unless the internals, ignition/carb etc. are the made to be the same and thats dollars unless you have a cheap source of those parts. But a 555 can be tweaked to match a 562xp stock.... my question is why? Just buy a 562xp and its a .. match of a 562xp.. :) . And can be built by ehp into a 562ehp. Guess you would have to add up the cost in parts to decide. (I happen to like my stock 555 as it is BTW)
Title: Re: 372XP X-Torq Modding
Post by: CR888 on December 31, 2015, 06:12:44 PM
Ported or not l would not even attempt to run a 60cc class saw 28" B/C in Aussie hardwood buried, not even with full skip. It would laugh at me!lol l like my 555 stock with a simple m/m and have it set up with 15" Windsor rsn in .325 with a 9pin (has to be 9pin if you wanna run .325 due to large spline). But l run a 20" bar on my mastermind ported ms660 and that will bog down instantly if you lift the rear handle with dawgs set. But an ehp 562xp sounds like it would be a special saw for limbing.......but a 16-18" bar is all l would want. Like my 550xp, my 555 performs well stock I think, Husky made both those saws impressive right out of the box IMO, whenever I run them I don't 'wish they were ported'. Instant throttle response, reasonable torque and great handling. I have a strato gutted ms261 that will happily run 16" B/C in the cut 10500-12800rpm.  But she has lost the high production advantage of the fuel efficient strato and fuel is burnt a 2x the pace of my stock one.lol
Title: Re: 372XP X-Torq Modding
Post by: nitehawk55 on December 31, 2015, 06:42:24 PM
About all I do with most is just a muffler Mod . I was going to have one of my 346NE's ported but for now just a muffler mod on it too .
I do have a 346oe that was ported a bit and it runs nice but I'm not out cutting wood and trying to impress anyone . Good running saw  , sharp chain is good enough :)
Title: Re: 372XP X-Torq Modding
Post by: 49er on December 31, 2015, 06:48:24 PM
CR888 said
It would laugh at me!lol l like my 555 stock with a simple m/m and have it set up with 15" Windsor rsn in .325 with a 9pin (has to be 9pin if you wanna run .325 due to large spline).


CR888 your 550 should have the small spline clutch drum and it will work on your 555. I put my 2253 drum on my 2260 and used an 8 pin rim. I have never tried a nine but I do have one.
Title: Re: 372XP X-Torq Modding
Post by: CR888 on December 31, 2015, 10:27:34 PM
Sweet!! Good to know as l bought a bunch of cheap stihl RM .325/063 chain that l need to use. I am off to check that out. I have been trying to do something similar with my ms261's that have the 'micro spline' and am thinking a ms260 clutch drum may be the ticket to making them 'small spline' and benefit from the use of AM rim sprockets which l have a heap of. Here in AU, a Stihl dealers retail micro spline rims for $33!!
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 01, 2016, 11:47:01 AM
any saw pretty much can be made to run if you want to spend enough money and throw enough parts at it , I myself donot like running anything over a 22 inch bar on any 562 , In my area I cut lots of white oak and that wood is really hard to get enough bar oil to the saw , A 24 inch setup is to dry on bar oil for me but at 22 inch it does the job . I only put the 28 inch on it to show people that the 562 can pull it and pull it well, in softwood ya maybe I would use the 28 inch more but not in this hardwood
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 02, 2016, 08:31:57 AM
I tore my 72 down yesterday and I'm happy with the results...as expected.  My  squish is now .025 and I also matched the lower transfers to the crank case.  I tried to post pics of the end result but they are the wrong format for this site. Question:  Have any of you trimmed the bottom of the cylinder to get better flow to the lower transfers on an XT?  I didnt, but there is a lot of obstruction that protrudes into the case.  Thanks

Josh B.

Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 02, 2016, 09:28:39 AM

And interesting video from one of the Pioneer's in this game...something for everyone here relative to technic and subjects like base gaskets etc...

https://www.youtube.com/watch?v=IauT5TZskqU
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 02, 2016, 10:32:58 AM
Good video but definitely beyond my capability at this point.  Can you offer an experienced opinion regarding trimming down the bottom of the cylinder near the transfers?  Thanks

Josh
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 02, 2016, 11:24:47 AM
I don't have a X-torq cut that way at this point. So really can't comment. Certainly with conventional 372 cylinders. My concern on those saws is the convoluted piston and resultant bearing surface change along with making certain making that change doesn't interfere with the "xtorq charge" channel cut in the piston. So at this point I wouldn't until I can see it, measure, then test for a period of time.

One thing I do see is now there are after market cylinders to test on! (search Husqvarna 372 X-torq in eBay for the 80 dollar option.) Maybe I'll get a bunch and see what I can do. I have to confess I moved right from conventional 372 cylinders on to 562's this past few months. Kind of skipped over the 372 xtorqs.  With the advent of low cost therefore low risk cylinders to hack at, maybe I'll revisit those.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on January 02, 2016, 11:50:41 AM
The OP is my brother and he and I did our 372's yesterday in his shop. Mine is the 75cc XPW and of course his is the XT...

With his top end off, I really don't see how this is a strato cylinder. It does not have the second butterfly along the carb that specifically feeds strato ports as I have come to understand them. What seems more in line to the XT 372 cylinder is that it has a 2-stage intake cycle. There is a small, single intake port in the customary location, and then there are the additional 2 intake ports about the same size as the transfers. Those "secondary" intake ports are being fed by the carb along with the main intake.

Am I missing something here that makes this a strato cylinder?? It is my understanding through learning here and other forums that the strato cylinders have separate fresh air ports that are isolated from the main fuel/air intake port that is regulated by a separate butterfly. This XT cylinder has none of those components or characteristics.

Edited to add: I am learning fast through the generous sharing of experience and wisdom here, but by no means do I claim to be the expert. Ready to stand corrected if I am incorrect in my assertion.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 02, 2016, 12:18:49 PM
No.. you are dead on. Nothing like the 562's or even the old 455's.  Just I was able to get more results with a tweaked 372 cylinder, or even the 52mm AM cylinders tweaked per amount of time spent with my knowledge set and limitations. And with the XPW... they have goofy transfers but even so, just getting the squish right and a simple muffler mod made a noticeable difference. So I have to defer to others for x-torq knowledge rather than re-invent that wheel. Only so much time! There are two guys who have spent time there. One "Terry Syd" has posted on the "strato" subject. The other is over at another site on specifics to the X-torq.

Maybe you can do some research and add to the collective knowledge here?? Would be nice to see someone focus on those X-torq cylinders.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 02, 2016, 12:35:13 PM
I didn't cut the cylinder for the exact reasons you stated...skirt support, piston port function and finally X-torque flow alteration.  The bottom of the cylinder has a very unique cut as compared to a traditional 372.  That alone made me pause I think that it may not be wise to grind on a prayer.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 02, 2016, 12:42:05 PM
Quote from: XP_Slinger on January 02, 2016, 12:35:13 PM
I didn't cut the cylinder for the exact reasons you stated...skirt support, piston port function and finally X-torque flow alteration.  The bottom of the cylinder has a very unique cut as compared to a traditional 372.  That alone made me pause I think that it may not be wise to grind on a prayer.

So now we have three folks (u me and red) interested in these things .. maybe we should put some time into them.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 02, 2016, 12:58:17 PM


So now we have three folks (u me and red) interested in these things .. maybe we should put some time into them.
[/quote]

Sounds like a plan.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 02, 2016, 01:03:04 PM
Quote from: RIDE-RED 350r on January 02, 2016, 11:50:41 AM
Ready to stand corrected if I am incorrect in my assertion.

Well Red....I have ONE assertion.. That is that since Eli Tomac flew away to Kawasaki...

The "Wing" doesn't have a "Prayer" this year in Super Cross... :)
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 02, 2016, 01:26:41 PM
Quote from: weimedog on January 02, 2016, 12:42:05 PM


So now we have three folks (u me and red) interested in these things .. maybe we should put some time into them.

Hey, count me in I have a 365 I plan on doing more mods to.
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 02, 2016, 01:42:54 PM
Quote from: RIDE-RED 350r on January 02, 2016, 11:50:41 AM
The OP is my brother and he and I did our 372's yesterday in his shop. Mine is the 75cc XPW and of course his is the XT...

With his top end off, I really don't see how this is a strato cylinder. It does not have the second butterfly along the carb that specifically feeds strato ports as I have come to understand them. What seems more in line to the XT 372 cylinder is that it has a 2-stage intake cycle. There is a small, single intake port in the customary location, and then there are the additional 2 intake ports about the same size as the transfers. Those "secondary" intake ports are being fed by the carb along with the main intake.

Am I missing something here that makes this a strato cylinder?? It is my understanding through learning here and other forums that the strato cylinders have separate fresh air ports that are isolated from the main fuel/air intake port that is regulated by a separate butterfly. This XT cylinder has none of those components or characteristics.

Edited to add: I am learning fast through the generous sharing of experience and wisdom here, but by no means do I claim to be the expert. Ready to stand corrected if I am incorrect in my assertion.

As far as the xt being a "strato," it is. It just has two paths through a single throat. The intake that has fuel air mix is relatively small but add the strato ports and the intake path is huge. The theory is get both sources of air into the cylinder where it is mixed together on the compression stroke. Very large potential for performance here.
Terry Sid posted a great thread on this in another location. The only experienced porter that has taken a shine to the 372xt I know of is ehp. Other porters are unenthusiastic at best. IMO.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 02, 2016, 02:44:24 PM
I think we should do first a Upstate New York GTG/Build off of 356/372 X-torqs this winter or spring time... all three of us, (Maybe Spike60 makes 4?). Do another one either late in the year or early next year with what we learned by doing and invite a few more if there is interest. Maybe getting a few involved we can develop a good solid build that's fun to run and others can replicate. This stuff isn't rocket science... but it does  take time and understanding of fundamentals to make it a worth while endeavor.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on January 02, 2016, 02:45:15 PM
Lol!! Point taken.. ;)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 02, 2016, 02:46:25 PM
I wonder why there isn't enthusiasm for x-torqs considering mine runs no different than my brothers XPW 75cc stock to stock.  I would think the porting crowd would be all over a saw that runs that strong in stock trim.  Strange.  Here's hoping the pro's take another look at them.  There's a lot of us running them.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 02, 2016, 03:16:11 PM
I can speculate. (But then have to go to work..:( ) It has to do with what you have both the tooling and experience for. A lot of what you do with the "conventional" cylinders translates from one to the next. So you can stay in your skill set/power curve work on them. It takes a lot of time and research to develop a build concept that's something your willing to put out in the market place. That combined with the onslaught of new Stilh and Husqvarna Strato saws like the 562/550 MS661/461 etc. the band width of those with the shops has limitations. Add that all up? 372xt's has less support than other saws. So ... maybe it would make sense to dive in and see what's available. As I mentioned, there seems to be more aftermarket support for them now. I have a blown up one on the bench but plan to just do my standard routine which is: ... muffler mod, no base gasket, re-sealed transfer caps, a intake boot (the latest of the four options!) ,cut a bit off the fin by the plug wire etc. It's getting "Nachi's" for bearings and new case seals as well.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 02, 2016, 04:47:47 PM
I was hoping Spike60 would chime in on this thread at some point, he seems to be one of the few that has any interest in the x-torq saws.  I would love to be somehow involved in a build off.  I may not bring experience to the table with regard to porting but I would be happy to help in any way I can.  I'm sure my brother Ride Red 350R would lend a hand as well.   Please keep me posted.
Title: Re: 372XP X-Torq Modding
Post by: CR888 on January 02, 2016, 05:57:32 PM
The strato design is what we have now on modern saws, builders I suppose are used to older prooven designs and methods. The xt has some good things going for it in its design but many find the xp easier to get the numbers they want with less work involved getting there. We don't have the xt in OZ, unfortunately we can only buy XP'S. (smiley face)
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on January 02, 2016, 08:31:25 PM
I would certainly be in for some shop time.

Just not sure I can muster the coin for another saw to experiment with... And I don't think I can part with my XPW to trade in on an XT.

I am in the beginning stages of skimming some $$$ out of the family budget to piece a 394 together.. I have a dirty cylinder..that's it so far! LOL!
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on January 03, 2016, 10:24:26 AM
Quote from: RIDE-RED 350r on January 02, 2016, 08:31:25 PM
And I don't think I can part with my XPW to trade in on an XT.

Lordy no, don't do that! The XPW is still the better saw.

But count me in for the GTG; sounds like fun. But we aren't going to borrow the "build off" term from those other guys. Those things are wrought with a lot of chest beating and arguing. We're going to call this a "tech seminar" GTG. Focus for this one being the XT saws. This what Walter and I do when we get together. Share and compare; put our heads together and build some saws. Be great to have some new minds adding to the conversation. We could focus on other chassis in the future.

That cylinder skirt on the XT jug cannot be removed like we do on the originals to open up the access to the transfers. It will expose the clean air channel cut in the piston. I of course learned that by ruining a cylinder.  :)  No biggie, cause it was a used one. And that's why Walt and I like used and aftermarket stuff for this learning process!

I have a 2166 that has been my test mule for this series. May have the raw materials for an orange version as well.

Be glad to have some of you guys join us and put some energy into these XT's. The originals get all the attention, and in a year or so all of the attention will be on the 572's. But the XT's are still selling in large numbers and will continue to be popular for a long time.
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 03, 2016, 12:35:24 PM
I never been to New York. It would be a fun trip. :)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 03, 2016, 02:34:48 PM
Especially with that machine in your avatar!
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 03, 2016, 06:41:40 PM
the XT design is pretty simple to figure out , well seems pretty easy to me . Yes you grind the bottom of the cylinder to remove restriction for the transfers ,but watch you donot grind to much towards the doors on the cylinder or you will have a big air leak , next end up at around 180 psi of compression, any more than that your not helping the saw , your hurting it . open up the strato in the intake so it gets fuel/air as well not just air , its not hard, you need to grind the plastic part that bolts to the carb that holds the air filter , take that bridge out so its like the older 372 style, next grind the rubber boot that goes between the cylinder and carb so its also just like the older 372 style . Yes you need to raised both the transfer and ext port and these engines are not to fussy , if you get a touch to high on your porting they still will pull good . you can widen the ext port lots . You can increase the flywheel timing lots as well . Will these beat the older 372/375 in 8 by 8 cookie cutting , most times no but there still strong , will they out cut the 372/375 in big hardwood , without a question , the XT's have a lot of torque and can handle cut after cut after cut . I use XT's everyday and cut good size big hardwood . I got a 390 and it only sees the landing some days , just way to heavier and not as nice to run in my books . Problem I see with some guys is they donot take a engine a part and figure it out , every design needs different mods and porting numbers , what works in a older 372 will not work on a XT just like what works on a 7900 will not work on a 372
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on January 03, 2016, 07:05:26 PM
Thanks for sharing Ed. You're one of the few guys who have figured out the XT's. I agree that each saw needs it's own recipe. Do you also get rid of the divider in the carb along with the intake boot and filter holder? I'm going to try some of your ideas.  :)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 03, 2016, 07:26:25 PM
Quote from: Spike60 on January 03, 2016, 10:24:26 AM
Quote from: RIDE-RED 350r on January 02, 2016, 08:31:25 PM
And I don't think I can part with my XPW to trade in on an XT.

Lordy no, don't do that! The XPW is still the better saw.

But count me in for the GTG; sounds like fun. But we aren't going to borrow the "build off" term from those other guys. Those things are wrought with a lot of chest beating and arguing. We're going to call this a "tech seminar" GTG. Focus for this one being the XT saws. This what Walter and I do when we get together. Share and compare; put our heads together and build some saws. Be great to have some new minds adding to the conversation. We could focus on other chassis in the future.

That cylinder skirt on the XT jug cannot be removed like we do on the originals to open up the access to the transfers. It will expose the clean air channel cut in the piston. I of course learned that by ruining a cylinder.  :)  No biggie, cause it was a used one. And that's why Walt and I like used and aftermarket stuff for this learning process!

I have a 2166 that has been my test mule for this series. May have the raw materials for an orange version as well.

Be glad to have some of you guys join us and put some energy into these XT's. The originals get all the attention, and in a year or so all of the attention will be on the 572's. But the XT's are still selling in large numbers and will continue to be popular for a long time.

A tech seminar is exactly what I would enjoy.  Good people, good food, cold drinks and chainsaws.  Does it get any better? 
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on January 03, 2016, 07:26:40 PM
I would love to get together for a tech seminar!

Maybe instead of having to source a whole other 372xt saw, those of us who are planning to get together could each get an aftermarket XT cylinder to bring with us??

I remember you showing in one of your vids Spike that the XT cylinder does not seat onto the traditional XP/XWP case without some modification due to there being more cylinder protrusion into the case... Having said that, I would be willing to bring my XPW to use as an experimental bottom end for the XT cylinder. Unless of course using the XT cylinder on my XPW bottom end would render the testing less than accurate due to the fact my XPW uses a traditional carb and intake??? Obviously in my case I would have to get the std size 372 piston as my XPW has a slightly larger bore...

BTW, I did some work on my XPW cylinder the other day while XP_Slinger was doing his XT...

I matched the transfers to the base gasket, opened up the lower transfers (wow that exhaust side had alot of material with that hump!), beveled and blended the transfer partitions, cut the cylinder skirts down to 2.500" as measured from the squish band on both sides, deleted the base gasket, and modded the muffler. I was very pleased with the end results.  ;D

Having some trouble figuring out how to post pics... otherwise I would show you what I did..
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 03, 2016, 07:31:30 PM
No need to tear into your XPW for a testing bottom end, since I have an X-torq we could use mine.  Can't wait for this gathering to happen.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 03, 2016, 07:34:24 PM
Quote from: ehp on January 03, 2016, 06:41:40 PM
the XT design is pretty simple to figure out , well seems pretty easy to me . Yes you grind the bottom of the cylinder to remove restriction for the transfers ,but watch you donot grind to much towards the doors on the cylinder or you will have a big air leak , next end up at around 180 psi of compression, any more than that your not helping the saw , your hurting it . open up the strato in the intake so it gets fuel/air as well not just air , its not hard, you need to grind the plastic part that bolts to the carb that holds the air filter , take that bridge out so its like the older 372 style, next grind the rubber boot that goes between the cylinder and carb so its also just like the older 372 style . Yes you need to raised both the transfer and ext port and these engines are not to fussy , if you get a touch to high on your porting they still will pull good . you can widen the ext port lots . You can increase the flywheel timing lots as well . Will these beat the older 372/375 in 8 by 8 cookie cutting , most times no but there still strong , will they out cut the 372/375 in big hardwood , without a question , the XT's have a lot of torque and can handle cut after cut after cut . I use XT's everyday and cut good size big hardwood . I got a 390 and it only sees the landing some days , just way to heavier and not as nice to run in my books . Problem I see with some guys is they donot take a engine a part and figure it out , every design needs different mods and porting numbers , what works in a older 372 will not work on a XT just like what works on a 7900 will not work on a 372

Excellent info, thanks for sharing.  I've been admiring your work on youtube...impressive.
Title: Re: 372XP X-Torq Modding
Post by: CR888 on January 03, 2016, 07:58:36 PM
I am yet to read a post from spike60 that has not been positive and insightful. Always good when he joins the party. Few guys have the knack to communicate and come off well in what they post whether they agree or disagree with what someone has said, he is definitely one of those guys. You gotta sell yourself before you can sell a product/service well, he has certainly mastered this process.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 03, 2016, 08:15:16 PM
I'll second that.  I haven't been a participating member on this forum for very long but it's easy to see that Spike60 is one of the guys that is eager to share his knowledge in a productive manner.  That goes for weimedog also.  I've learned a lot over these couple days. Thanks fellas
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 03, 2016, 10:53:37 PM
Spike, gut everything , first thing you will notice is the saw will run a lot better and be far better to adjust on the carb compared to stock , the idle is far better than stock , You should blend the 2 intake air ports so no major restriction for the air/fuel mixture to get into the cylinder . Every XT that I have built is still running strong and I have only built these saws for guys that cut timber so most have a lot of hours on them , Most guys ran 385/390's and parked them . I never sent a XT to the USA only in Ontario . I have heard lots about the bore lining coming off after porting and stories like that but in most cases that's not the cylinders fault , that's the guy running the porting tools fault , Using way to coarse of a porting burr does that, the 7900 will do the same . I have seen pictures but never had a cylinder lining lift on me 
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 03, 2016, 10:54:58 PM
Now I have heard some of the XT's come with a different carb , I have never seen that here , all came with same carb so far
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 04, 2016, 12:02:27 AM
Home from work .. wow! A lot has gone on! Pretty much any Sunday the farm road isn't snowed in works. I have a set of J-red 2166 cases that need a purpose, maybe that will be a test bed for XT top ends with EHP inspired mods. I see the suggestion on gutting all plastic dividers from air filter to cylinder AND raising transfers & exhaust. Any idea on the ending blow down & exhaust opening? Any surgery to the intake port/casting on the cylinder? Looks like there is a fair amount of "meat" around that intake should working those make sense. Thanks for both the research and defining a direction to forge ahead with on these.
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 04, 2016, 04:03:14 PM
I kinda like the fuel mileage of my XT, well really not having to go to my gas can as often.Cost of the fuel is not important.
A rubber intake manifold and plastic intake is all that would be needed to go back to strato. But the saw may not like it what with the changes in port timing.
Running the saw each way would be an interesting experiment.
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 18, 2016, 09:59:27 AM
   I removed the black coil and reinstalled the original blue coil. I think it runs better with the retarded ignition at idle and a good advance at high rpm.
   I have heard the compression release is too great on this saw. I believe it is because on restarts while using the "CR" it does not like to start unless ya give it a good windup. So I am thinking of trying a "CR" from another saw like my 2253.
   Has anyone else tried this? 
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 18, 2016, 03:58:58 PM
Just put a "plug" in it. Solves the issue. :)
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on January 18, 2016, 04:44:41 PM
Quote from: ehp on January 03, 2016, 10:53:37 PM
Spike, gut everything , first thing you will notice is the saw will run a lot better and be far better to adjust on the carb compared to stock , the idle is far better than stock , You should blend the 2 intake air ports so no major restriction for the air/fuel mixture to get into the cylinder.

Thanks for the advice Ed! Did just what you said, and the saw really runs nice. Doesn't mind being leaned on. You're right on the idle settling down too. Carb needed a fair amount of adjustment from where it was to adapt to the changes.
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 18, 2016, 06:24:59 PM
Spike not a problem , the xt motor is a very good design just needs a hack to make it run abit better  ;D. I'm to the point I donot like running a stock xt just because of how they idle and throttle response compared to modded
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 18, 2016, 09:39:02 PM
play with the flywheel to Spike, advance the flywheel timing say even 1/4 width of the key way helps as well , makes them come alive when you nail the gas  ;D
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on January 19, 2016, 08:56:20 AM
In my experience, a little more timing within reason is a plus with alot of different things.

This may or may not apply to the specific application we are discussing (372XT) But I would only caution that between the bump in compression with the gasket delete, and advance of ignition timing, it may bring your fuel octane requirements up a little higher than pump gas can provide.

Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 20, 2016, 01:00:26 PM
Quote from: Spike60 on January 18, 2016, 04:44:41 PM
Quote from: ehp on January 03, 2016, 10:53:37 PM
Spike, gut everything , first thing you will notice is the saw will run a lot better and be far better to adjust on the carb compared to stock , the idle is far better than stock , You should blend the 2 intake air ports so no major restriction for the air/fuel mixture to get into the cylinder.

Thanks for the advice Ed! Did just what you said, and the saw really runs nice. Doesn't mind being leaned on. You're right on the idle settling down too. Carb needed a fair amount of adjustment from where it was to adapt to the changes.

Think I just found a project for this afternoon.  Did you gut the intake and blend the dual intake ports as Ed suggested?
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 20, 2016, 01:06:06 PM
Quote from: 49er on January 18, 2016, 09:59:27 AM
   I removed the black coil and reinstalled the original blue coil. I think it runs better with the retarded ignition at idle and a good advance at high rpm.
   I have heard the compression release is too great on this saw. I believe it is because on restarts while using the "CR" it does not like to start unless ya give it a good windup. So I am thinking of trying a "CR" from another saw like my 2253.
   Has anyone else tried this?

My XT absolutely refused to start using the decomp until I removed the base gasket and bumped compression to 180psi.  Now it works as it should somewhat indicating that the decomp is a bit too tight as you suggested.  Compression was 145psi prior to the gasket delete.
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 20, 2016, 03:13:19 PM
Quote from: XP_Slinger on January 20, 2016, 01:06:06 PM


My XT absolutely refused to start using the decomp until I removed the base gasket and bumped compression to 180psi.  Now it works as it should somewhat indicating that the decomp is a bit too tight as you suggested.  Compression was 145psi prior to the gasket delete.
[/quote]

My desire is to have an super easy start, on hot restarts. I want to try 
a smaller decomp from another saw. Right now it does not like hot restarts when using the decomp. It will do it if ya spin it fast enough. :o
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 20, 2016, 06:41:14 PM
Quote from: 49er link=topic=87633.msg1351854#msg13
/quote]

My desire is to have an super easy start, on hot restarts. I want to try 
a smaller decomp from another saw. Right now it does not like hot restarts when using the decomp. It will do it if ya spin it fast enough. :o
[/quote]

Don't blame you, mine frustrated me a little when the decomp wouldn't reset.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 20, 2016, 09:57:39 PM
A question. .. I have a bone stock 2172. Not quite a shelf queen but one I want to keep nice... should I tweak it? Or leave it be.
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 20, 2016, 10:23:23 PM
Quote from: weimedog on January 20, 2016, 09:57:39 PM
A question. .. I have a bone stock 2172. Not quite a shelf queen but one I want to keep nice... should I tweak it? Or leave it be.
I say tweak it. Try it. Report back. And then, I'll know what to do to mine. 8)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 21, 2016, 06:22:54 AM
Quote from: weimedog on January 20, 2016, 09:57:39 PM
A question. .. I have a bone stock 2172. Not quite a shelf queen but one I want to keep nice... should I tweak it? Or leave it be.

I know the feeling, my 357XP is near new and I had reservations about "tweaking" it because it's so nice.  Needless to say, that reservation went away after running my brothers tweaked 357.  Mods done right will only make your saw nicer IMO.  What are you going to do?
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on January 21, 2016, 06:24:41 AM
Quote from: XP_Slinger on January 20, 2016, 01:00:26 PM

Think I just found a project for this afternoon.  Did you gut the intake and blend the dual intake ports as Ed suggested?

Yes I did, and it worked nice. :)   Think of it in 4 steps. Filter holder, carb divider plate, intake boot, and then the blending of the top and bottom intake ports. One look at the carb side of the filter holder and you'll see why that has to get cleaned out! The carb divider slides out easy by removing the throttle shaft. This may allow the choke plate to go a little overcenter, but the choke lever will keep it where it needs to be.

Plan to do his suggestion on the timing advance today, but probably won't run it til the weekend.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 21, 2016, 07:01:15 AM
Quote from: Spike60 on January 21, 2016, 06:24:41 AM
Quote from: XP_Slinger on January 20, 2016, 01:00:26 PM

Think I just found a project for this afternoon.  Did you gut the intake and blend the dual intake ports as Ed suggested?

Yes I did, and it worked nice. :)   Think of it in 4 steps. Filter holder, carb divider plate, intake boot, and then the blending of the top and bottom intake ports. One look at the carb side of the filter holder and you'll see why that has to get cleaned out! The carb divider slides out easy by removing the throttle shaft. This may allow the choke plate to go a little overcenter, but the choke lever will keep it where it needs to be.

Plan to do his suggestion on the timing advance today, but probably won't run it til the weekend.

Thanks for the response Spike.  I took the air filter divider out when I deleted the base gasket.  I'll get into mine this weekend and remove the carb divider and blend the intake.  And by blend I assume we are putting knife edges on them to smooth out the flow.  Correct?  Cant wait to hear your report on how she runs.  Left field question:  is it true that to turn a 2166 x-torq into a 2172 all that has to be done is removing the transfer restrictors?  Thanks
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on January 21, 2016, 09:02:59 AM
Yes on both the knife edge and transfer cover points.

However, I'm afraid I've detected a little baloney in this thread.  :)  A certain individual has tossed out the thought of going into his mint 2172 and doing these mods to it. There's NO WAY he's going to be doing that right yet; given how well I know said individual. I'm sure that a proven recipe will have to be documented and tested on some other ugly carcass before he messes with that nice 2172.  ;D 
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 21, 2016, 09:46:56 AM
Quote from: Spike60 on January 21, 2016, 09:02:59 AM
Yes on both the knife edge and transfer cover points.

However, I'm afraid I've detected a little baloney in this thread.  :)  A certain individual has tossed out the thought of going into his mint 2172 and doing these mods to it. There's NO WAY he's going to be doing that right yet; given how well I know said individual. I'm sure that a proven recipe will have to be documented and tested on some other ugly carcass before he messes with that nice 2172.  ;D

:D  The problem with an itch is you eventually have to scratch it :)  I get the feeling Weimedog wanted to diversify the thread with some Red n' Black.   Just so happens that I am, for some reason, REALLY wanting a JRed.  A friend of mine is getting a smoking deal on a new 2166 from a dealer for $549 (Hence the transfer restrictor question).  As to why I want it?  Still haven't figured that one out ::)  Might be because of my dads 87' 455 that both me and Ride-Red cut our teeth on as kids.
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 21, 2016, 10:14:00 AM
Quote from: Spike60 on January 21, 2016, 09:02:59 AM
Yes on both the knife edge and transfer cover points.

However, I'm afraid I've detected a little baloney in this thread.  :)  A certain individual has tossed out the thought of going into his mint 2172 and doing these mods to it. There's NO WAY he's going to be doing that right yet; given how well I know said individual. I'm sure that a proven recipe will have to be documented and tested on some other ugly carcass before he messes with that nice 2172.  ;D

I like some baloney. There is nothing wrong with being conservative.  :D
I still don't know if I want to go non-strato with this saw. A faster saw is desirable but a saw is not fast when your pouring fuel in it.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on January 21, 2016, 11:32:26 AM
That was Spike's way of saying... leave it stock for now. :) BUT he is right. Have two bloody carcasses to try things out on first.. :) One red and one Orange. ( Need another new top end though.... ) ALSO this gives a reason for those older boots to avoid the trash can. And on the "knife" edge, that's not actually hogging out the entire dividers, just making a more aero dynamic shape for the mixture to work around to get to the intake ports.... does it make sense to "favor" the traditional port (lower one)?? How about widening that lower port a bit after blending the divider to favor it vs. the strato ports? Inquiring minds want to know... :) That along with an offset key and a "no base gasket build" sounds like a start.. Has anyone figured out what timing works best for these? Exhaust/Blow down numbers after that intake tweak?

(Still want to do a "simple mans" old style 365 build )
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 21, 2016, 07:38:25 PM
Quote from: 49er on January 21, 2016, 10:14:00 AM
Quote from: Spike60 on January 21, 2016, 09:02:59 AM
Yes on both the knife edge and transfer cover points.

However, I'm afraid I've detected a little baloney in this thread.  :)  A certain individual has tossed out the thought of going into his mint 2172 and doing these mods to it. There's NO WAY he's going to be doing that right yet; given how well I know said individual. I'm sure that a proven recipe will have to be documented and tested on some other ugly carcass before he messes with that nice 2172.  ;D

I like some baloney. There is nothing wrong with being conservative.  :D
I still don't know if I want to go non-strato with this saw. A faster saw is desirable but a saw is not fast when your pouring fuel in it.

Sounds like we need to test the fuel mileage.  I would be surprised if it were any worse than a traditional 372xp, bit that is purely speculation.  I bet Ed or Spike could offer some info on the strato vs de-stratofied fuel economy.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on January 21, 2016, 08:54:53 PM
I think I'm going to bring my Spike-ified XPW along to see how it compares to these XT's when we get done playing with them...  ;D

Heck, I'll probably bring the Spike-ified 357 too... Just because..  8)

And yeah, Dad's old 455 is a keeper.. We need to figure out what's ailing that saw Josh. I want to use it..
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 21, 2016, 09:01:13 PM
Quote from: RIDE-RED 350r on January 21, 2016, 08:54:53 PM
I think I'm going to bring my Spike-ified XPW along to see how it compares to these XT's when we get done playing with them...  ;D

Heck, I'll probably bring the Spike-ified 357 too... Just because..  8)

And yeah, Dad's old 455 is a keeper.. We need to figure out what's ailing that saw Josh. I want to use it..

You and your Dubya!  I'll bring some W's! But I don't think Winchesters will fit into saw shop talk time with Spike and company.  Lol...;) and yes we need to get dad's saw squared away.
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 22, 2016, 01:18:48 PM
yes a stock 365/372 cuts longer per tank but I donot get paid by that , I get paid by how much timber I put on the ground . Also a ported 365/372 puts more timber on the ground per minute compared to a stock so its not a big difference . I think the older stock 372 may burn more fuel per tree than a ported 365/372 xt
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 22, 2016, 05:55:51 PM
Quote from: ehp on January 22, 2016, 01:18:48 PM
yes a stock 365/372 cuts longer per tank but I donot get paid by that , I get paid by how much timber I put on the ground . Also a ported 365/372 puts more timber on the ground per minute compared to a stock so its not a big difference . I think the older stock 372 may burn more fuel per tree than a ported 365/372 xt

  I take care of some loggers saws for them and they measure fuel consumption in trees per tank.   
  Ok you and Spike convinced me. I am going to get my Foredom tool out and start grinding. I always knew I would sooner or later.  smiley_roller
I will need to get a baseline in this ash I got drug up first.
    This winter storm has made for unfavorable conditions here today. Fortunately, I don't have to work outside in bad weather anymore.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 22, 2016, 10:08:56 PM
Quote from: ehp on January 22, 2016, 01:18:48 PM
yes a stock 365/372 cuts longer per tank but I donot get paid by that , I get paid by how much timber I put on the ground . Also a ported 365/372 puts more timber on the ground per minute compared to a stock so its not a big difference . I think the older stock 372 may burn more fuel per tree than a ported 365/372 xt

Makes sense, thanks for the info.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 26, 2016, 05:33:40 PM
Quote from: Spike60 on January 21, 2016, 06:24:41 AM
Quote from: XP_Slinger on January 20, 2016, 01:00:26 PM

Think I just found a project for this afternoon.  Did you gut the intake and blend the dual intake ports as Ed suggested?

Yes I did, and it worked nice. :)   Think of it in 4 steps. Filter holder, carb divider plate, intake boot, and then the blending of the top and bottom intake ports. One look at the carb side of the filter holder and you'll see why that has to get cleaned out! The carb divider slides out easy by removing the throttle shaft. This may allow the choke plate to go a little overcenter, but the choke lever will keep it where it needs to be.

Plan to do his suggestion on the timing advance today, but probably won't run it til the weekend.

Did you get a chance to run your saw Spike? 
Title: Re: 372XP X-Torq Modding
Post by: 49er on January 27, 2016, 03:47:36 PM
Did you get a chance to run your saw Spike?

Waiting patently arent we Slinger. ;)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 27, 2016, 05:12:54 PM
Quote from: 49er on January 27, 2016, 03:47:36 PM
Did you get a chance to run your saw Spike?

Waiting patently arent we Slinger. ;)

Yep
Title: Re: 372XP X-Torq Modding
Post by: ehp on January 27, 2016, 10:52:10 PM
I run my saws every day  ;D and their all XT's , sometimes I run the 390 on the landing
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 28, 2016, 06:01:41 AM
Quote from: ehp on January 27, 2016, 10:52:10 PM
I run my saws every day  ;D and their all XT's , sometimes I run the 390 on the landing

Loud n' clear... :) 
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 01, 2016, 09:15:43 PM
  Well, my 365xt is no longer strato. I took the divider out of the air filter holder and the manifold. I ran it some in 24 inch ash and smaller poplar. My main comment is darn ehp anyway. EDITED BY ADMIN FAMILY SITE. KNOCK IT OFF.
  The saw ran really well. It has always seemed a little temperamental but not now. The idle is rock solid even when I flop it from side to side. I was going to compare cut times but I forgot and  already had the carb off and didn't feel like putting it back on. Cutting the ash the rpm's ranged between 10.5k and 12k depending how hard I leaned on it. Next, I plan on grinding aluminum instead of plastic. I am going to need some advice on that.
   One other thing I did was replace the compression release with one off my 2253. This change allows a very easy hot restart. Normally it's not a big deal but occasionally
when I am in an awkward position I will use the decomp. By the way my 2253 will not start hot or cold with the decomp off the 365. I will purchase another decomp. One has an "A" on it the other is a "C".
   
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 02, 2016, 07:22:33 PM
Quote from: 49er on February 01, 2016, 09:15:43 PM
  Well, my 365xt is no longer strato. I took the divider out of the air filter holder and the manifold. I ran it some in 24 inch ash and smaller poplar. My main comment is darn ehp anyway. EDITED BY ADMIN FAMILY SITE. KNOCK IT OFF.
  The saw ran really well. It has always seemed a little temperamental but not now. The idle is rock solid even when I flop it from side to side. I was going to compare cut times but I forgot and  already had the carb off and didn't feel like putting it back on. Cutting the ash the rpm's ranged between 10.5k and 12k depending how hard I leaned on it. Next, I plan on grinding aluminum instead of plastic. I am going to need some advice on that.
   One other thing I did was replace the compression release with one off my 2253. This change allows a very easy hot restart. Normally it's not a big deal but occasionally
when I am in an awkward position I will use the decomp. By the way my 2253 will not start hot or cold with the decomp off the 365. I will purchase another decomp. One has an "A" on it the other is a "C".


I havent gotten around to gutting the strato stuff on mine yet,  ive been having too much fun running my 357.  Where are you grinding aluminum?  Transfers or intake?
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 02, 2016, 07:43:24 PM
Also wonder about fuel usage
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 02, 2016, 07:59:55 PM
I feel I'm getting about 1500 to 1600 feet of log scale to the tank in red oak, hard maple falling in the bush
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 03, 2016, 06:03:17 AM
Quote from: ehp on February 02, 2016, 07:59:55 PM
I feel I'm getting about 1500 to 1600 feet of log scale to the tank in red oak, hard maple falling in the bush

Question for ya Ed:  is any of the fuel/air charge from the strato ports retained for combustion once the strato dividers are removed?  I ask this because the strato ports are opened and closed by the top of the piston, not the skirt.  Correct? Seems to me that the charge would be blown out the exhaust.This question is simply to increase my knowledge, not concerned about fuel mileage.  Thanks
Title: Re: 372XP X-Torq Modding
Post by: CR888 on February 03, 2016, 07:24:06 AM
Quote from: Spike60 on January 21, 2016, 06:24:41 AM
Quote from: XP_Slinger on January 20, 2016, 01:00:26 PM

Think I just found a project for this afternoon.  Did you gut the intake and blend the dual intake ports as Ed suggested?

Yes I did, and it worked nice. :)   Think of it in 4 steps. Filter holder, carb divider plate, intake boot, and then the blending of the top and bottom intake ports. One look at the carb side of the filter holder and you'll see why that has to get cleaned out! The carb divider slides out easy by removing the throttle shaft. This may allow the choke plate to go a little overcenter, but the choke lever will keep it where it needs to be.

Plan to do his suggestion on the timing advance today, but probably won't run it til the weekend.
Spike I have not done any testing to verify my thoughts, but would'nt removing the divider within the carb slow air velocity through the venturi? And as the main fuel circut relies on this to deliver fuel, could this modd hamper fuel delivery? Quad dividers are added in the performance 2T motocross world to increase bottom end torque as it vastly improves velocity and fuel at lower speeds. My thinking is far from correct in all circumstances but have you done some testing to confirm he removal increases power? Maybe at WOT under load the way a saw is run it acts as an obstruction? Interested to hear your thoughts. Ta
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 04, 2016, 01:42:31 PM
Quote from: CR888 on February 03, 2016, 07:24:06 AM
Quote from: Spike60 on January 21, 2016, 06:24:41 AM
Quote from: XP_Slinger on January 20, 2016, 01:00:26 PM

Think I just found a project for this afternoon.  Did you gut the intake and blend the dual intake ports as Ed suggested?

Yes I did, and it worked nice. :)   Think of it in 4 steps. Filter holder, carb divider plate, intake boot, and then the blending of the top and bottom intake ports. One look at the carb side of the filter holder and you'll see why that has to get cleaned out! The carb divider slides out easy by removing the throttle shaft. This may allow the choke plate to go a little overcenter, but the choke lever will keep it where it needs to be.

Plan to do his suggestion on the timing advance today, but probably won't run it til the weekend.
Spike I have not done any testing to verify my thoughts, but would'nt removing the divider within the carb slow air velocity through the venturi? And as the main fuel circut relies on this to deliver fuel, could this modd hamper fuel delivery? Quad dividers are added in the performance 2T motocross world to increase bottom end torque as it vastly improves velocity and fuel at lower speeds. My thinking is far from correct in all circumstances but have you done some testing to confirm he removal increases power? Maybe at WOT under load the way a saw is run it acts as an obstruction? Interested to hear your thoughts. Ta

That's what I am thinking as well.  Seems that by removing the restrictive dividers the saw will lose some low end torque but gain power in the top end.  Which to me makes sense for a chainsaw.  Now two guys on this thread have gutted the strato dividers and like the results which is making it really tempting for me to do the same.  I've been holding out for some tangible evidence that the saw is stronger.  I know EHP's saws are very strong but they aren't just de-stratified, they're fully woods ported which makes me wonder if gutting the strato stuff is really worth it without the porting to accompany it.  So far what I've seen is the idle stabilizes but my saw doesn't have the idle issues that others seem to be experiencing.  I'm still patiently waiting... ;D
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 05, 2016, 11:17:10 AM
why would you loose torque , you now are feeding fuel/air mixture threw the strato 2 ports . Plus you donot cut with a saw at 4,000 rpms , you cut at 8000 plus rpms . , I'm not telling anyone what to do , you guys/gals can make up your own minds , Spike asked me a question and I answered it with what I do and happy to tell him what I do . I donot talk porting numbers as that is a sure way to cause trouble as the number is only part of porting, more has to do with shape , corners, width . Plus lets just say donot believe everything you read on the internet on what numbers guys are using .
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on February 05, 2016, 12:04:04 PM
And I do appreciate you sharing that advice Ed. Never hurts to learn something.  :)

I like the way the saw is running. Last run after messing with the timing was hard to really notice anything. I didn't have the ideal file to nibble on the flywheel key, and was starting to think I was wrecking it. So, I only took a little bit off and may not have accomplished anything.

I'm still curious about Walter's question on blending the upper and lower intakes on the cylinder as far as favoring either the upper or lower. I really just split the difference between them. But I'm wondering if favoring the lower, or more traditional intake would be better.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 05, 2016, 09:30:28 PM
Quote from: ehp on February 05, 2016, 11:17:10 AM
why would you loose torque , you now are feeding fuel/air mixture threw the strato 2 ports . Plus you donot cut with a saw at 4,000 rpms , you cut at 8000 plus rpms . , I'm not telling anyone what to do , you guys/gals can make up your own minds , Spike asked me a question and I answered it with what I do and happy to tell him what I do . I donot talk porting numbers as that is a sure way to cause trouble as the number is only part of porting, more has to do with shape , corners, width . Plus lets just say donot believe everything you read on the internet on what numbers guys are using .

I certainly appreciate the information you've shared and in no way am I  trying to discredit the information youve provided.  All of my questions are coming from simply wanting to have a better understanding of these mods and how they effect the dynamics of the engine.  If my questions were recieved in any other context it was not intentional.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 06, 2016, 11:59:38 AM
Think I want to try some things based on ehp's inspiration. The carb:
I think the reason I would remove the divider in the carb is so all of the air going through gets mixed with fuel where it would seem to me if the divider is in, there would still be two steams leaving the carb; one with and one without fuel air mixture. And both streams will then go both to the stratos ports and also to the lower end as the boot divider it now gone. Yes I understand you can tune around this and the churning in the bottom end would mix those two...but this is one of those instinct things. Effectively that carb is the size of a 385xp's, and if we figure out how to make a strato saw flow more fuel air to get more power that carb size will be an asset...SO I start with that premise. All dividers gone.

Intake: I haven't looked yet but if I can, I want to maximize the height & width of the port going to the bottom end while "shaping" the cast divider to favor that lower intake port. Also want to increase the intake duration some, how much? Not certain yet. That port is so small and with a taller Strato piston that case volume has to be larger; duration can be a good thing.

Transfers: They are smaller than the old style but this is partly because of the interaction with the strato passages and piston. Still want to first try and widen and to what ever extent possible tweak to enhance more flow. Starting with stock timing numbers until I understand more about these things.

Exhaust: Widen without changing timing as I don't yet understand these cylinders yet. This along with a gutted and modded muffler is simply a starting point.

Interestingly enough I did receive a Huztl X-torq top end. $60 bucks delivered (eBay bid vs. buy now) A lot of tweaking will be needed as it came with fins / dividers in the tranfers as a 365 would. SO they go away first along with opening as much as the casting material will allow those transfers.

Also they have radically reduced the openings of the strato ports on the cylinder side. Interesting. I plan to leave them in that state. They also have the intake to crank case port the same size as stock. I hope to blend to favor that lower intake port as well as both increase the duration a few degrees, raise and widen it some too.

The quality of the casting material looked to be quite good without porosity and will certainly be a "cheap" way to explore places to grind :) I plan to wreck some of those before putting the final pattern on a good OEM casting.

THATS how I plan to start this journey. And THANKYOU ehp for being a pioneer giving us both a direction and feed back based on experience to launch the rest of us lemmings to the cliff.

April time frame before what I'm doing now gets to video. Just a time thing...I don't have any.
Title: Re: 372XP X-Torq Modding
Post by: sawdusty1 on February 06, 2016, 02:10:31 PM
I can't imagine grinding on the internals of my new $800 372 xtorq.   Mine cuts like a bat out of hell.  I believe the Husqvarna engineers know way more than we do.  I have a 181se, 55, 350 too, all bought new.  Have done nothing to them through the years and they cut good to this day.  My Dad taught me to don't fix it if it ain't broke.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on February 06, 2016, 04:24:34 PM
Well, alot of things past and present, leave the factory in a state where improvements can be made... One classic example I give you is the Chevy 350. Most run of the mill 350's left Detroit making about 200hp give or take depending on year/model.. People that wanted more and had the billfold to back it up could get the same engine making 600hp.

The number of other examples out there is all but infinite...

You have to look at it from the standpoint of the factory... They want to build a product that is a good blend of reliability, performance, and keeping the pricepoint competitive with the competition. Are stock saws really good, if not great?? Absolutely. But that does not mean gains cannot be had from methodical modifications. The trade-off for performance gains is usually a bit shorter average service life. And that can be greatly influenced by the maintenance habits of the owner. I'm sure there are people out there who can ruin a stock saw faster than some guys will wear out a modded saw speaking in terms of engine operating hours.

I have a 357xp. It was the first new saw I ever bought. I have loved that saw from day 1. A few months ago, I decided to stick my toe in the water of modifying it. I deleted the base gasket, did some clean-up and case matching to the lower transfers, and made a second exhaust port in the muffler. I can tell you with 100% certainty that these little mods made quite a noticeable difference. My brother (XP Slinger) has a 357 as well and last week just had the modded muffler. We ran both saws in the woods last weekend, and on one occasion we swapped saws. We both noticed a pretty stark difference between the two when we swapped to the other. Xp Slinger has since tossed his 357 base gasket into the trash can.. :)

But at the end of the day, different strokes for different folks is the only rule that really matters. Some folks prefer to leave their saws stock, and that is OK. Others like to tinker, as I do....

I was always pleased with my 357 when it was still stock. But I have no regrets whatsoever about the improvements I have made to it. And I had fun in the process.   
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 06, 2016, 05:28:55 PM
I'm not exactly tearing into an 800 dollar saw either truth b known.. have a set of 2166 cases from one that fried it's bearings....building from that junk pile. And a 50 dollar top end. I might have 200 into this project when I'm done...;)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 06, 2016, 06:24:46 PM
Quote from: weimedog on February 06, 2016, 05:28:55 PM
I'm not exactly tearing into an 800 dollar saw either truth b known.. have a set of 2166 cases from one that fried it's bearings....building from that junk pile. And a 50 dollar top end. I might have 200 into this project when I'm done...;)

Not me, I'll be doing all of this on my only 372.  With all the knowledge on here between ehp, Spike60 and yourself, I am confident I'll be all grins running my modified X-torq.
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 06, 2016, 10:38:39 PM
I ran my modified 365xt today and I did grin. Seriously, it is like a different saw with the intake divider removed. It started on the third pull, using ehp's method. It idled perfectly while I put on my gear and returned to idle after long cuts without a bobble.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 07, 2016, 07:35:44 AM
Quote from: 49er on February 06, 2016, 10:38:39 PM
I ran my modified 365xt today and I did grin. Seriously, it is like a different saw with the intake divider removed. It started on the third pull, using ehp's method. It idled perfectly while I put on my gear and returned to idle after long cuts without a bobble.

Thanks for sharing :) 
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 07, 2016, 05:04:00 PM
the stratos ports are yes ports but not like the other intake ,ext, transfer ports so you need to think abit on what husky wanted those ports to do , main idea was to put clean air into the transfer ports to help lower the emissions in the ext , the clean air helps flush the crap out of the cylinder , , grinding them does help but not a ton as the charge has to go threw the port into the slots of the piston and then the charge gets dumped into the transfer port , I grind some on these ports and some on the piston to help . . If you want the motor to pull at a higher rpm you have to change the porting numbers to get the higher rpms 
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 07, 2016, 06:09:23 PM
Quote from: ehp on February 07, 2016, 05:04:00 PM
the stratos ports are yes ports but not like the other intake ,ext, transfer ports so you need to think abit on what husky wanted those ports to do , main idea was to put clean air into the transfer ports to help lower the emissions in the ext , the clean air helps flush the crap out of the cylinder , , grinding them does help but not a ton as the charge has to go threw the port into the slots of the piston and then the charge gets dumped into the transfer port , I grind some on these ports and some on the piston to help . . If you want the motor to pull at a higher rpm you have to change the porting numbers to get the higher rpms

Thanks for the explanation!  My brain was way wrong on how they actually operated.  I thought the stratos were opened and closed by the top of the piston sending the fresh air across the piston and out the exhaust.  I would've gutted my strato stuff today but I spent the day pulling firewood out instead.  I'll get to it eventually, trying to take advantage of this clear weather to get some wood out.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on February 07, 2016, 06:20:25 PM
And we got a darned good amount done today didn't we!  8)

Man those 357s run!!!  ;D smiley_bounce
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 07, 2016, 06:50:29 PM
Quote from: RIDE-RED 350r on February 07, 2016, 06:20:25 PM
And we got a darned good amount done today didn't we!  8)

Man those 357s run!!!  ;D smiley_bounce

Yes we did!  I can't put my 357 down!
Title: Re: 372XP X-Torq Modding
Post by: CR888 on February 07, 2016, 07:52:45 PM
I have noticed generally strato ope has bigger venturi carbs. I think prior to this technology, building a saw or ope to fit within epa emission regulation meant either restricting either the exhaust and or the carb. Walbro documents will tell you straight and simple what is an 'epa' carb and what is not. We have all seen the other extreme in mufflers where a cat is installed (stuffed) into it. (always felt for them little pussy cats being crammed into a tin can)lol. With the advance of strato tech my opinion is they no longer need to restrict muffler flow and run small venturi and tiny jetted carbs as the inherent nature of the strato design lets a lot less unburnt charge escape. I have had good results using carbs off strato ope in other non strato ope designs of similar displacement. It can make a night and day difference just giving a two stroke a carb it desires. Torque can be improved big time, not so much rpm increase but throttle response and torque. I fit a strato blower carb onto a non strato older trimmer and the power increase was huge, actually while its hard to measure without proper expensive equipment it was more noticeable than some port jobs I have had by bench mark internet builders. I am not for a second taking anything away from the good work many of them do but mods to increase power do not have to be all done with a foredom and lathe. Cost effective mods to carburation, blueprinting, timing and exhaust can be done in a simple manner and can yield a good result. Especially when l face shipping charges that usually meet the cost or at least 50% of the work done itself.
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 07, 2016, 09:06:11 PM
Nice wright up 888. And yes shipping charges add considerably to the cost of a port job.
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on February 08, 2016, 07:49:37 AM
Quote from: XP_Slinger on February 06, 2016, 06:24:46 PM
Quote from: weimedog on February 06, 2016, 05:28:55 PM
I'm not exactly tearing into an 800 dollar saw either truth b known.. have a set of 2166 cases from one that fried it's bearings....building from that junk pile. And a 50 dollar top end. I might have 200 into this project when I'm done...;)

Not me, I'll be doing all of this on my only 372.  With all the knowledge on here between ehp, Spike60 and yourself, I am confident I'll be all grins running my modified X-torq.

Most of what we have been discussing here are not high risk changes where you have a chance to wreck the top end, so have some fun with it. Changes to the filter holder, carb and boot are reversable. Blending the upper and lower intakes isn't something that could screw up the cylinder.

Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 08, 2016, 10:23:25 AM
Understanding the Strato theory, I'm kind of hoping the AM top end with its smaller than stock "Strato" ports helps get more mixture through the bottom end and transfers to make this act more like a traditional 372. I haven't put a degree wheel on this one and certainly haven't seen any timing numbers on line yet, but the eye ball calipers says it has decent numbers with a lower blow down right the way it Is, so that's why starting by simply widening those ports first. Possibly a second AM version with a cut cylinder/popup arrangement, raised exhaust to move the RPM's up a tad (Also the blow down increases .. might have to cut the transfers to keep it reasonable depending on the measured results AFTER a pop up piston). Without a starting point defined, I will use something along these lines for a "guide". Exhaust 100 degrees ATDC, Blow Down 22 degrees. Intake 80 degrees BTDC. Plus or minus depending on what I find. Anyone already get some good numbers figured out? Might save a cylinder or two! I'm simply taking a shot in the dark and hoping to hear a "ding!" then work from there.

I do wonder if that taller than original 372 piston is one of the reasons they aren't allowed to spin from the factory. Same crank and bearings as the origional... heavier and taller piston HAS to do something with the dynamics.
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 08, 2016, 04:39:34 PM
I don't think I have seen any port timing numbers on the 372-365xt's. I don't have a clue what would work.
For sure a lighter slug would allow more rpm's and be easier on the bottom end but I don't think even a properly ported xt would exceed the 13.3K blue coil limit in the cut. I remember Spike and someone discussing bearing issues a few years ago but the root cause was improper assembly at the factory. Long sense corrected.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 08, 2016, 05:22:55 PM
Quote from: Spike60 on February 08, 2016, 07:49:37 AM
Quote from: XP_Slinger on February 06, 2016, 06:24:46 PM
Quote from: weimedog on February 06, 2016, 05:28:55 PM
I'm not exactly tearing into an 800 dollar saw either truth b known.. have a set of 2166 cases from one that fried it's bearings....building from that junk pile. And a 50 dollar top end. I might have 200 into this project when I'm done...;)

Not me, I'll be doing all of this on my only 372.  With all the knowledge on here between ehp, Spike60 and yourself, I am confident I'll be all grins running my modified X-torq.

Most of what we have been discussing here are not high risk changes where you have a chance to wreck the top end, so have some fun with it. Changes to the filter holder, carb and boot are reversable. Blending the upper and lower intakes isn't something that could screw up the cylinder.

100% agree.  I have no worries about my saw being negatively affected by these simple mods.  I could've caused way more problems when I opened up the lower transfers when I deleted the base gasket. 
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 09, 2016, 07:02:20 PM
I just uploaded 2 images of my lower transfers into my gallery.   One pic shows one of the transfers before I worked on it.  What do you think guys?
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 09, 2016, 07:44:09 PM
   I advanced my ignition timing today. I removed about one third of the key with a triangular file. For a little bit I felt like Spike did, like I was messing up. Usually when I feel that way it is because I am messing up. ;) After removing some metal, I realized as long as I left some trailing key material, I could always dial the flywheel back to the original location.
With the key cast into the flywheel there is really no good way to measure  how much ya remove.
   After assembly, the saw started like it always does on the third pull. The next thing I noticed was the idle speed was a little higher(chain wanted to turn). So I slowed it down a little. I went and did some test cuts in 24 inch ash I have up at the barn. There were no wow moments, it just cut strong like it always does. A small surprise was the hot restarts when using the decomp. One short easy pull and it starts. Hot starts are easier than my 2253. Which reminds me a I do have my 2253 decomp in this saw.
  Now, I have to go look at pictures of Slinger's lower transfer ports.
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 09, 2016, 07:50:07 PM
Quote from: XP_Slinger on February 09, 2016, 07:02:20 PM
I just uploaded 2 images of my lower transfers into my gallery.   One pic shows one of the transfers before I worked on it.  What do you think guys?

Those look like you been porting for years, nice and smooth. Have ya run it yet?
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 09, 2016, 08:10:53 PM
Quote from: 49er on February 09, 2016, 07:50:07 PM
Quote from: XP_Slinger on February 09, 2016, 07:02:20 PM
I just uploaded 2 images of my lower transfers into my gallery.   One pic shows one of the transfers before I worked on it.  What do you think guys?

Those look like you been porting for years, nice and smooth. Have ya run it yet?

Yes I have and it runs good.  Unfortunately I cleaned up these transfers on the same day that I deleted my base gasket so I can't speak to what difference it made by itself.  Just looking at how mis-matched the cylinder was to the crank case before I did this has me thinking it must have done some good. 
Title: Re: 372XP X-Torq Modding
Post by: beenthere on February 09, 2016, 08:42:23 PM
XP
Put your images in your post for us to see...

The "copy and paste" instructions are below each pic, if you go to your gallery and click the pic first.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 09, 2016, 09:17:21 PM
(https://forestryforum.com/gallery/albums/userpics/40531/20160101_142458.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 09, 2016, 09:20:18 PM
(https://forestryforum.com/gallery/albums/userpics/40531/20160101_153215.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 09, 2016, 09:21:39 PM
Quote from: beenthere on February 09, 2016, 08:42:23 PM
XP
Put your images in your post for us to see...

The "copy and paste" instructions are below each pic, if you go to your gallery and click the pic first.

Thanks for the assist.  I didn't know I could copy paste the pics into the thread
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on February 10, 2016, 03:47:14 PM
^^^This guy^^^

Does all this work to his 372, and then tells me last night he is toying with the idea of trading it in on a new 390! LOL!

But anyway, I did roughly the same thing to my XPW cylinder except I did as Spike recommends for most saws and trimmed the cylinder skirt adjacent to the transfers down a bit. The edges measure 2.500" from the squish band. That was about the only sure fire way I could think of to make sure that they came out even. I did use the depth gauge on our vernier calipers to measure.

I also took out the humps in the exhaust side transfers as recommended by most people whose opinions I trust.

I know it's not an XT... I just wanted to brag a little. ;)
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on February 10, 2016, 03:58:58 PM
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160101_144659482.jpg)
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160101_142145378_HDR.jpg)

This pic shows stock config on left, and my work finished up on the right.
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160101_142109184.jpg)

Showing trimmed cylinder skirt
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160101_142540946_HDR.jpg)
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160101_142125813.jpg)

Even though mine isn't an XT, I plan on bringing it to our little GTG to see what you guys think of it. :)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 10, 2016, 08:04:32 PM
Quote from: RIDE-RED 350r on February 10, 2016, 03:47:14 PM


I know it's not an XT... I just wanted to brag a little. ;)

Hijacker!!!  Lol! 

And I'm not trading it in, I was just pontificating.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 11, 2016, 01:54:20 AM
I think this is going to be interesting..to see if we can get a "simple tools" X-torq to run as well as a tweaked 372..:)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 11, 2016, 06:05:32 AM
Quote from: weimedog on February 11, 2016, 01:54:20 AM
I think this is going to be interesting..to see if we can get a "simple tools" X-torq to run as well as a tweaked 372..:)

Any thoughts on what I did to my transfers?
Title: Re: 372XP X-Torq Modding
Post by: CR888 on February 11, 2016, 06:19:12 AM
With the price of oem husky cylinders plummeting recently, would a good option for you guys in the US (who cannot by OE 372xp's) be to purchase an OE cylinder kit and fit it too an XT? Pretty sure cases etc are the same. Just an option for those who seek a new saw but like the old edition. They mod well the xp's, you could use the xt carb too. The epa may not like my advice but most of us don't like them either!
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 11, 2016, 10:06:05 AM
Good post 888. Definitely something to think about.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 11, 2016, 10:27:45 AM
thought about that... but two interesting things have become apparent to me in my area. First a growing number of folks like their 372xt's better because they say they pull harder than their old standard 372's did (More torque??) . True or not, its where they are. Second, you can't buy an old style 372 new anymore. Haven't been able to since 2010. And the more x-torq's out there means yet even more interested in tweaking them. If they don't have to drop a hundred dollar bill....they would prefer not to. SO back to simple things (for simple minds like mine?) to make them run better without dropping big dollars into parts is of growing interest around here at least. So for me, I want to learn how to make these X-torqs run stronger and if possible keep some of their strong points in play such as fuel usage vs. older saws. Compression... compression compression! (A place to start) So for me its a two track game plan. First is as I articulated before...to make them run at all costs. Second is play simply the compression game to see where that gets me....BUT have a pile of 562 stuff to do first.
Title: Re: 372XP X-Torq Modding
Post by: mad murdock on February 11, 2016, 01:18:27 PM
I just have to say-thank you all for this thread.  I am watching with much interest 8)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 11, 2016, 07:51:30 PM
Quote from: mad murdock on February 11, 2016, 01:18:27 PM
I just have to say-thank you all for this thread.  I am watching with much interest 8)

Glad it's helping you out.  Theres a lot of good guys on here that have helped me a ton.  Do you have an XT that you're thinking about tinkering with?  Fair warning, if you start  you won't want to stop...lol.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 15, 2016, 06:27:40 PM
Ok fellas, I know I've been dragging my feet but if all goes well I will be gutting the strato dividers on my XT this coming weekend.  Thinking about taking a couple videos of the process and posting them for folks that are interested in this thread.  There seems to be quite a few since this thread has been viewed over 3100 times.  Any other suggestions while I've got the top end off for blending the intake?
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 16, 2016, 10:25:18 AM
Quote from: XP_Slinger on February 15, 2016, 06:27:40 PM
Ok fellas, I know I've been dragging my feet but if all goes well I will be gutting the strato dividers on my XT this coming weekend.  Thinking about taking a couple videos of the process and posting them for folks that are interested in this thread.  There seems to be quite a few since this thread has been viewed over 3100 times.  Any other suggestions while I've got the top end off for blending the intake?

XP are you planing on doing your porting in stages. I know you have done the lower transfers. While you have it apart are you going to do the intake port, exhaust port and upper transfers? Are you just going to widen them or go for a predetermined duration?
    So far, I have ground out my transfer covers, opened the muffler, removed the base gasket, gutted the strato intake dividers, modified my tank vent and advanced my ignition timing.
The ignition timing made a noticeable difference with the originator blue coil. I started it after sitting for about a week, when the temperature was it the teens. The saw started on the third pull using the decomp. Hot restarts were super easy with the decomp too. As I have said before this is the decomp from my 2253 Jonsered.
    I am not going to do any grinding on the cylinder until I can find some timing numbers that work well.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 16, 2016, 10:53:02 AM
Quote from: 49er on February 16, 2016, 10:25:18 AM
   
XP are you planing on doing your porting in stages. I know you have done the lower transfers. While you have it apart are you going to do the intake port, exhaust port and upper transfers? Are you just going to widen them or go for a predetermined duration?
    So far, I have ground out my transfer covers, opened the muffler, removed the base gasket, gutted the strato intake dividers, modified my tank vent and advanced my ignition timing.
The ignition timing made a noticeable difference with the originator blue coil. I started it after sitting for about a week, when the temperature was it the teens. The saw started on the third pull using the decomp. Hot restarts were super easy with the decomp too. As I have said before this is the decomp from my 2253 Jonsered.
    I am not going to do any grinding on the cylinder until I can find some timing numbers that work well.

Niner,

   While it would definitely be the opportune moment to do some additional grinding on the exhaust, intake and upper transfers, I am going to leave them alone this time.  The first reason being as you stated, waiting to discover some solid numbers to avoid the "Willy Nilly" approach.  Maybe we will figure that part out at the GTG this spring?  Secondly, I would like to stay true to the "No Cost Approach" that this thread is focused on.  I think getting into porting is a bit much for most (not all) weekend wrenchers looking for cheap ways to get some more grunt out of their XT saws.  My saw is configured like yours in a few ways; Base gasket deleted(.024 Squish) , muffler modded & reshaped lower transfers.  My intent is to clearly document the process of removing the strato dividers and blending the intake via pictures or videos for interested readers.  Once complete I'll go after the timing as ehp and Spike60 described in previous posts.  Maybe do some test cuts of before and after?  Heck, I could even do a side by side with my brothers 372XPW that is similarly modded once all is said and done.  I've got a brand new TSB Lightweight bar and new Stihl RS chain that is just begging to be put through some wood ;D I FINALLY ordered a tach for tuning and hopefully it arrives by Friday so I can test the saw with a proper tune @ 13,000rpm.  Any other thoughts on what bases could be covered?
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 16, 2016, 11:24:18 AM
XP, you probably know this but the blue coil in these saws are limited to 13.3K. So just watching the tack the saw could sound like it is 4-stroking @ 13K but your really on the limiter. Ya need ta approach it from the rich (low rpm side) or it will fool ya.
I tried a black unlimited coil but did not like it as well. The 346 coil I think would be a good option. It is limited to 14K something and has an advance rate like the blue coils.

I gotta go work on my transfer case now. :'(
Title: Re: 372XP X-Torq Modding
Post by: mad murdock on February 16, 2016, 03:00:15 PM
Quote from: XP_Slinger link=topic=87633.msg1361263#msg1361263 date=
/quote]

Glad it's helping you out.  Theres a lot of good guys on here that have helped me a ton.  Do you have an XT that you're thinking about tinkering with?  Fair warning, if you start  you won't want to stop...lol.

XP- no i dont have an XP. I have a 2005 vintage XPW. I also have a number of other saws, mostly yellow and black, and am thinking of tinkering with them. It does sound like an addictive passtime. Keep up the good work 8)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 16, 2016, 04:13:57 PM
Quote from: mad murdock on February 16, 2016, 03:00:15 PM
Quote from: XP_Slinger link=topic=87633.msg1361263#msg1361263 date=
/quote]



XP- no i dont have an XP. I have a 2005 vintage XPW. I also have a number of other saws, mostly yellow and black, and am thinking of tinkering with them. It does sound like an addictive passtime. Keep up the good work 8)

Gotta love that XPW :)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 18, 2016, 02:50:28 PM
Quote from: 49er on February 16, 2016, 11:24:18 AM
XP, you probably know this but the blue coil in these saws are limited to 13.3K. So just watching the tack the saw could sound like it is 4-stroking @ 13K but your really on the limiter. Ya need ta approach it from the rich (low rpm side) or it will fool ya.
I tried a black unlimited coil but did not like it as well. The 346 coil I think would be a good option. It is limited to 14K something and has an advance rate like the blue coils.

I gotta go work on my transfer case now. :'(

Yep.  I always start rich and work up slowly.  Good luck with your T-Case
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 18, 2016, 05:11:35 PM
(https://forestryforum.com/gallery/albums/userpics/40531/20160218_163857.jpg)

Got my tach and degree wheel today.  I'm itching to get to work on my XT saturday or sunday.  Would anyone want timing numbers for the saw in its current config with the deleted base gasket? 
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 18, 2016, 06:44:42 PM
Quote from: XP_Slinger on February 18, 2016, 05:11:35 PM
(https://forestryforum.com/gallery/albums/userpics/40531/20160218_163857.jpg)

Got my tach and degree wheel today.  I'm itching to get to work on my XT saturday or sunday.  Would anyone want timing numbers for the saw in its current config with the deleted base gasket?

Well Yesssssss.
   
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on February 19, 2016, 04:12:21 PM
This is gonna be fun!  8)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 06:26:35 PM
Well I finally got it done today and I like the results.  I'll get working on posting up the pics and commentary.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 06:57:40 PM
Step 1: Filter Mount

Pretty straight forward, I clipped the majority of the divider out with dikes then smoothed everything out with a dremel. TIP: keep the dremel speed low, too much speed melts the plastic very fast and makes it a little more time consuming to clean up after the cutting is done.

(https://forestryforum.com/gallery/albums/userpics/40531/20160220_124723.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 07:00:26 PM
Step 2: Carb Divider

  This step is a little more intricate. To remove the divider you have to remove the throttle butterfly and shaft as Spike60 previously stated. Once the shaft is removed simply pull the divider out of the carb via the slot that it resides in. My divider needed gentle persuasion with needle nose pliers. TIP: The retention screw for the butterfly had low grade thread locker on it. I reapplied low grade locker upon reassembly for cheap insurance to keep a saw killing screw out of the crank case.

(https://forestryforum.com/gallery/albums/userpics/40531/20160220_121726.jpg)


Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 07:03:40 PM
Step 3: Intake Boot

This step is very delicate, if you're not careful you WILL cut a hole in your intake boot. Take your time and pay close attention to what collateral damage could be done by portions of your blade that aren't cutting the intended material. The hobby knife in the picture worked especially well for this because the shape of the blade allowed me to push through the rubber vs saw through it.

Before:
(https://forestryforum.com/gallery/albums/userpics/40531/20160220_115031.jpg)

After:
(https://forestryforum.com/gallery/albums/userpics/40531/20160220_120502.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 07:07:33 PM
Step 4: Cylinder Intake

This step is more experimental than the previous ones. We have been kicking around 2 schools of thought, 1st; blend the edges between the ports to smooth out the flow, or 2nd; blend them but make the flow favor the main (lower) intake passage. I opted for the 2nd option. I continued the intake roof angle up through the material between the main and strato passages. I didn't make the intake wider down lower because the intake boot was actually fit to its shape very closely. The stratos were largely untouched with the exception of bringing the edge together with the lower intake.

Before:

(https://forestryforum.com/gallery/albums/userpics/40531/20160220_114953.jpg)

After:

(https://forestryforum.com/gallery/albums/userpics/40531/2016-02-20_17_53_44.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 07:23:39 PM
I am glad I took the time to do this, I am very pleased with how it runs. I can definitely lug this saw harder than I could before.  Obviously not a race saw but what would have stopped the chain before doesn't, it just keeps eating.  I tuned it to 12,900 no load and it's holding 11,200 +/- 100 in the cut.  I also took the opportunity and advanced the timing by about 1/4 of the key width.  Ride-Red helped me get a video of first cuts after tuning in some 18" frozen white ash, I'll work on getting that video posted.  Sorry, no XPW race, we had to call it quits to watch our kids. I also got some timing numbers that I will post up.

So what do you think about the in the cut RPM?  It sounds frickin great!  Better than it ever has.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 07:34:59 PM
Almost forgot, we had to make an adapter for the crank in order for the degree wheel to clear everything.  We used a 1.25" sleeve and welded on an 8mm x 1.0 nut for the crank and a 6mm x1.0 nut for the wheel side. All sourced at our local hardware store for under $3.

(https://forestryforum.com/gallery/albums/userpics/40531/20160220_151953.jpg)

(https://forestryforum.com/gallery/albums/userpics/40531/20160220_152004.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 08:25:29 PM
https://youtu.be/KdTJOJfS9do
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 20, 2016, 09:25:23 PM
Timing numbers are as follows:

Exhaust - open @ 100° ATDC, duration 160°

Transfer - open @ 121° ATDC, duration 134°

Intake - open @ 73° BTDC, duration 150°

I did my best, it's tough to tell when the ports actually opened or closed just by using light because of the angles you're viewing them at.  Especially the transfers.  Any suggestions for more accurate methods?
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on February 21, 2016, 08:59:06 AM
Good write-up Joshy... Like something you would find in a service manual.

I concur on the difficulty in getting spot-on accurate measurements. There is a little margin for error using the light method... Or are we being too picky???

I did see a vid MM posted about how to mark the cylinder where you need to stop grinding at a desired degree point using a piston ring pushed into place by the piston.

I wonder if we could figure a way to use this method??
Title: Re: 372XP X-Torq Modding
Post by: 49er on February 21, 2016, 09:47:59 AM
   It seems to me the saw has plenty of  blowdown. I wouldn't think it needed more than it has already. But that is just a guess.
    Have you noticed an improvement in the idle or starting. I did in my saw after gutting the strato and advancing ignition.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 21, 2016, 10:54:05 AM
Quote from: 49er on February 21, 2016, 09:47:59 AM
   It seems to me the saw has plenty of  blowdown. I wouldn't think it needed more than it has already. But that is just a guess.
    Have you noticed an improvement in the idle or starting. I did in my saw after gutting the strato and advancing ignition.

Yes I did. 

   Cold starting - i just grabbed it off the shelf and I got the first pop after 3 pulls using the decomp.  Previously it took 4 to 5 pulls.  Hot start is the same as before, 1 pull with with or without the decomp.

Idle characteristics - I would describe the idle as "surgy" prior to doing this work.  And as you can hear in the video, the idle consistently settles to a nice even tone.  And I still have to richen up the low side a bit but my slow jet stopper is hanging up somehow, thought I removed it a while ago.   I would definitely call this a success.

   I feel no need to adjust blow down either.  I am however considering widening the exhaust a bit and working on the exhaust passage itself.  This is fun and I want to keep this thread going with all interested parties on here.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 21, 2016, 11:38:09 AM
Really cool stuff! Moves some speculation to "it going to happen" territory

Glad you tried the "favoring" the intake.... Now I know vs. speculate that's where I'm going with that! Two things... first since we are making these act like a conventional AND that intake is...SMALL maybe a bit more duration is another definite vs. speculation, I plan to get mine in the high 70's on the first iteration, like 78 degrees BTDC. Also I was wanting to know if the intake could be widened and also at top dead center is there any material to remove to get a full opening without exposing the bottom edge of the piston skirt and/or making the "bridge" too small between the intake and strato's. I wouldn't mess with the blow down if its in that 20-21 range but I'm tempted to widen the transfers around to the intake side some on mine. Also plan to leave the exhaust timing alone and widen it some. A muffler mod done in moderation makes even more sense now. I'll do my typical blocking off the stock outlet and adding a 3/4 in dia tube to the upper pto side corner... :)

The "ball park" numbers I'm usually looking to get to on my "F-ugly 2" Chinese BB's ( and other 372 variants I guess ) are along these lines: Exhaust 100 ATDC, Blowdown 20 degrees, intake 79 BTDC. Squish .020. They both start and idle just fine with solid torque. And the muffler mod as said above.

Just a question... I haven't looked at the system yet, sort of tied up with 562's at the moment. Do you see anyway of bleeding the x-torq passages to the crank case without killing the entire x-torq system? Or if that doesn't make sense AND now there is "charge" vs air, could it be entered into the combustion chamber sooner adding a little "kick" to the existing charge?

One thing I LIKE about this entire concept is it added oil along the side of that piston vs. having straight air. Always wondered if there are any sign of increased wear in those where the x-torq passages are to the intake side. I do notice on the 562's its not uncommon to see light seize on the intake side even before the exhaust side....just askin   :-\

Hoping to build a video on the two I will build in April time frames...
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 21, 2016, 11:55:00 AM
Quote from: weimedog on February 21, 2016, 11:38:09 AM
Glad you tried the "favoring" the intake.... Now I know vs. speculate that's where I'm going with that! Two things... first since we are making these act like a conventional AND that intake is...SMALL maybe a bit more duration is another definite vs. speculation, I plan to get mine in the high 70's on the first iteration, like 78 degrees BTDC. Also I was wanting to know if the intake could be widened and also at top dead center is there any material to remove to get a full opening without exposing the bottom edge of the piston skirt and/or making the "bridge" too small between the intake and strato's. I wouldn't mess with the blow down if its in that 20-21 range but I'm tempted to widen the transfers around to the intake side some on mine. Also plan to leave the exhaust timing alone and widen it some. A muffler mod done in moderation makes even more sense now.

Just a question... I haven't looked at the system yet, sort of tied up with 562's at the moment. Do you see anyway of bleeding the x-torq passages to the crank case without killing the entire x-torq system?

I did not check how far the piston skirt traveled above the intake.  But there is plenty of room to raise the passage leading to the port if you were to raise the port window.  I know it's hard to truly see what I did in my pic but I followed the the exact same angle of the port roof and that angle is maintained all the way to the port window.  The sleeve was also cut to match this angle.
    I 100% agree that blow down is nice where it's at.   Not excessive making the gas move out slowly, not lacking and stuffING the transfers too bad. On the next tear down I will be making the exhaust wider to increase cylinder evacuation efficiency with its generous blowdown.
    The way I can see to get the strato charge to the crank case is to put some windows on the piston.  But the good and bad of that is highly speculative.  Location would be a dificult monster to nail down because if placed in the wrong place they would vent built crank case pressure.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 21, 2016, 12:10:03 PM
I added some stuff to that post.... ::) curious on your thoughts
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 21, 2016, 04:32:11 PM
Quote from: weimedog on February 21, 2016, 12:10:03 PM
I added some stuff to that post.... ::) curious on your thoughts

I had every intention of making the main intake passage wider.  But upon inspection  I discovered that the intake boot was already slightly smaller than the passage opening.  Because of this, I left the width alone.  The way my mind analyzed it was the added width would be largely useless and create additional turbulence in the intake path when flowing through a smaller boot into the wider intake.  Same story goes for the bottom of the intake, the boot match is very close and any additional opening would not have increased the flow volume the way I would have wanted it to.  I think the better route would be a round OE style intake boot if it will fit, then we would definitely get the benefits of opening the intake passage on all sides.

   As far as timing goes, I can't even make a recommendation as I am still learning this process. 

   Sure wish I rook a picture of my cylinder ports so I could think and try to visualize how the strato ports could be "re-purposed" in the manners you have asked about.  Without a cylinder in front of me sliding with a piston up and down it's tough for me to evaluate possibilties.
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 21, 2016, 05:21:40 PM
Your doing ok, you could do a lot more grinding on the intake side to better flow the ports , you did no grinding on the 2 top stratos ports , main thing is the part between the 2 ports where is pretty wide but not thinned down to more of a point, next donot be scared  about grinding the part you did to a lot more of a thin edge and the edge can be moved further back into the cylinder . On degreeing a motor I never use finding TDC , way to much chance of a mistake on degrees the ports that way , I only degree the port opening with going down and up then divide by 2 so that also helps lessen the chance of a mistake , On doing transfers I put a bright light in the ext port and look threw the sparkplug hole , lots do it the other way but I can see the transfer pretty easy this way . You guys are worried about blow down degrees and the numbers your using is very very safe , I got less blowdown than you guys , Less blowdown makes the motor pull a lot harder on topend as you have to raise your transfer port numbers to get less blowdown , Once you have gone to far the motor will have no torque and be very lazy but with these numbers your a ways from that happening , keep playing . The only way you really learn anything is to do it yourself , having someone else tell you learns you nothing
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 21, 2016, 05:31:49 PM
Quote from: ehp on February 21, 2016, 05:21:40 PM
Your doing ok, you could do a lot more grinding on the intake side to better flow the ports , you did no grinding on the 2 top stratos ports , main thing is the part between the 2 ports where is pretty wide but not thinned down to more of a point, next donot be scared  about grinding the part you did to a lot more of a thin edge and the edge can be moved further back into the cylinder . On degreeing a motor I never use finding TDC , way to much chance of a mistake on degrees the ports that way , I only degree the port opening with going down and up then divide by 2 so that also helps lessen the chance of a mistake , On doing transfers I put a bright light in the ext port and look threw the sparkplug hole , lots do it the other way but I can see the transfer pretty easy this way . You guys are worried about blow down degrees and the numbers your using is very very safe , I got less blowdown than you guys , Less blowdown makes the motor pull a lot harder on topend as you have to raise your transfer port numbers to get less blowdown , Once you have gone to far the motor will have no torque and be very lazy but with these numbers your a ways from that happening , keep playing . The only way you really learn anything is to do it yourself , having someone else tell you learns you nothing

Thanks for your input it is very much appreciated.  I couldn't agree more, the best way to learn is to do it. 

   I was going to knife edge the blunt area between the strato passages but decided not to on the premise of getting as much charge as I could to flow into the main intake.  I'll grind as you suggested next time I pull the top end.  Thanks again for sharing your experience.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 22, 2016, 06:14:53 PM
Phase 2 Plan

1 - Remove covers and clean up the transfer passages, not making them bigger as I don't want to kill velocity. I will also raise transfer timing a few degrees while the covers are off.

2 - Re-work the intake on the carb side as ehp suggested.

3 - Widen exhaust port, then open and polish the exhaust passage leading to the muffler.

4 - Give it a few more degrees of intake duration.

Thoughts?
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 23, 2016, 04:41:34 PM
did you not remove the cylinder base gasket to tighten squish up, By doing that you all ready lowered all the port timing , you increased the intake port open timing by doing that but lowered both your transfer and ext port timing , you need to increase your ext port timing and the transfer timing , right now your less than stock on both transfer and ext. and that lowers your powerband rpm numbers
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 23, 2016, 07:48:52 PM
Quote from: ehp on February 23, 2016, 04:41:34 PM
did you not remove the cylinder base gasket to tighten squish up, By doing that you all ready lowered all the port timing , you increased the intake port open timing by doing that but lowered both your transfer and ext port timing , you need to increase your ext port timing and the transfer timing , right now your less than stock on both transfer and ext. and that lowers your powerband rpm numbers

Excellent point...Thank you!  I am recalling now that this subject came up a while ago in this thread. 

    Thinking out loud here....taking the lack of a base gasket into account, I will raise & widen the exhaust as you suggested, then I will also raise the transfers, but a bit higher than I raise the exhaust to slightly reduce blowdown in an attempt to strengthen top end pull.

   I am now understanding the benefit of cutting the base and squish band vs deleting the gasket.  As I raise the exhaust I will loose some of the compression I gained by deleting the gasket.  It seems this could be compensated for by cutting the base and squish band through tuning the squish to get the desired compression with the exhaust port opening sooner.  Within reason of course.

Am I on target with this hypothesis?  Maybe not, been a long day. 

Once again ehp, thank you for sharing your experience.  You're really helping me stay between the lines when I get off track a little.  Squirrel!
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 27, 2016, 06:43:28 PM
I did some more work today, pics will be up in a bit.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 27, 2016, 07:28:10 PM
   Before I tore into the saw today I put a degree wheel on it again.  This time I used a dial indicator to find TDC because I wanted more accuracy.  My new numbers prior to porting are as follows:  Exhaust opens @ 100* ATDC, Transfers open @ 121* ATDC, Intake opens @ 77* BTDC.  Figured I'd get that out there to correct my numbers that I posted last weekend...Sorry about that guys.

The previously posted plan was execute with the exception of raising the exhaust, I did however widen it. 



Here's a pic of my transfer port after working on it.  New timing is 116*

(https://forestryforum.com/gallery/albums/userpics/40531/20160227_142845.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 27, 2016, 07:31:32 PM
Next up...Exhaust. I forgot to get a pic of the window side of the port to show the widening, sorry.

(https://forestryforum.com/gallery/albums/userpics/40531/20160227_154807.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 27, 2016, 07:35:45 PM
Rework on the intake per ehp's advise.  Hoping I got close to what was described.

(https://forestryforum.com/gallery/albums/userpics/40531/20160227_161640.jpg)

(https://forestryforum.com/gallery/albums/userpics/40531/20160227_161650.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 27, 2016, 07:43:23 PM
  All in all I'd say the day was a success because I didn't snag a ring and the saw doesn't run worse. I could only run it for a couple cuts because it got dark and I have to say I didn't get the "Wow" I was hoping for.  This may be because I didn't tune it with my tach, more to follow.  If getting it tuned in doesn't wake it up I'll be going back in to raise the exhaust.  Yes, this could've been done today but I'm trying to get a feel for what does what to the saw when you change port timing.  My brothers XPW on the other hand came to life and ran like a beast with similar changes in port timing.  XPW - 1, XT - 0 on the day.  :(
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 28, 2016, 07:41:42 AM
You got some of what I said correct, maybe its just I said it wrong , you 2 upper stratoes ports I wanted the bridge between them brought to a point , from the pictures it kind of looks flat now but maybe it just the way I see things , what are your transfer ports numbers now . Your going to find you need to tune the saw and that will only be learned by playing with it and making cuts in a log , If your rich it will not scream like it should but still cut pretty good . Do some tuning and see how it cuts
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 08:10:54 AM
I'm heading out now to tune it.  And you're seeing things correctly I didn't touch the bridge between the strato ports, my mistake I'll get after those today.  My numbers are now as follows:
Exhaust - 100°, transfers - 116°, Intake - 77° BTDC.

  The saw doesn't run worse, but it feels about the same.  Still strong.  If a tuning session doesn't wake it up I'll be tearing it down to raise the exhaust a couple degrees as you previously suggested. 
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 28, 2016, 08:29:26 AM
also do yourself a favor , port time like this , shine a light in either the sparkplug hole and look threw the ext port or put light in ext port and look threw sparkplug hole , have piston up near TDC and bring piston down slow and as soon as you see any light in the ext port , stop , set degree wheel at o , turn motor over by going down to BDC then back up until light is gone , read degree wheel and divide by 2 , that is your port degree of opening and this way is far more accurate and less chance of screw up , finding TDC is not a good way of doing porting timing , if your off just .005 on TDC that changes your port timing a lot . You posted you raised your transfers 5 degrees of opening, that's lots and that should of took you abit to do so I am wondering if maybe your off abit on TDC. I hear and read the way you are doing your port timing is how most guys are doing it but its up to you but believe me how many guys cannot do it proper , Just for a joke, port timing your way then port time my way and add both ways together , you should end up with 180 , if not then there is a mistake some where and you already know that my way your got the port timing very close cause of seeing the light
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 09:47:47 AM
Ok fellas...tuning got it going.  Initial cuts with the tac showed it holding 11.5k in the cut.  An improvement over the previous 11.2k.  Did a few cuts then did a plug chop to check tune, it was rich.  So I started leaning it out 1/8 of a turn at a time, then doing five cuts then a plug chop.  The plug started to turn a dark grey at 12.5k.  It got too grey for my liking at 12.7k!  It had great power at 12.7k but since it's not a race saw I dialed the tune back to 12k +/- 100 in the cut for longevity sake.  It runs great!  I made all my cuts in 15" (measured) very hard seasoned white ash.  My chain is a near new stihl RS, the only cuts on it were the ones I did for the video in this thread and a couple last night.  I am now very pleased with the advances in performance I've made.  And lesson learned, don't jump to conclusions before a proper tune.  I should know better but we all make impulsive mistakes.  I'll get a video up later when my brother shows up to be my camera man.

    I would say my brothers XPW still has it in the torque department but I would expect that with its larger displacement.  And the intent of this build wasn't to beat up on his dubya, although I was expecting them to be more even with the X-torqs reputation for being on par with an XPW in torque aspect.  My saw is definitely no dog, if I want to I can push it through the wood hard.  Not something I like to do, I would rather just keep the chain sharp and let it do the work.

   The big question now is : do I go back in to raise the exhaust a bit and grind the strato bridge as ehp recommends?  Or, do I leave it be and be happy?  Choices choices.

BTW...this would have never happened were it not for those with experience sharing their knowledge.  Cannot stress how grateful I am.  Thank you.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 10:04:13 AM
Quote from: ehp on February 28, 2016, 08:29:26 AM
also do yourself a favor , port time like this , shine a light in either the sparkplug hole and look threw the ext port or put light in ext port and look threw sparkplug hole , have piston up near TDC and bring piston down slow and as soon as you see any light in the ext port , stop , set degree wheel at o , turn motor over by going down to BDC then back up until light is gone , read degree wheel and divide by 2 , that is your port degree of opening and this way is far more accurate and less chance of screw up , finding TDC is not a good way of doing porting timing , if your off just .005 on TDC that changes your port timing a lot . You posted you raised your transfers 5 degrees of opening, that's lots and that should of took you abit to do so I am wondering if maybe your off abit on TDC. I hear and read the way you are doing your port timing is how most guys are doing it but its up to you but believe me how many guys cannot do it proper , Just for a joke, port timing your way then port time my way and add both ways together , you should end up with 180 , if not then there is a mistake some where and you already know that my way your got the port timing very close cause of seeing the light

Thanks very much for describing this method of timing ports.  Accuracy was a concern of mine that's why I switched to a dial indicator.  My brother set mine up using a piston stop and doing the math after I ported my saw and his method showed my timing had not changed.  Knowing that was impossible, I set up the dial indicator again and presto, I saw my 5° change in timing.  Your method looks even better, I took a screen shot of your post and I will definitely use it the next time I degree a port.  I also did as you described by shining a bore light (for rifles) in the chamber and looked through the exhaust port for first light.  I also did this for the transfers with the covers off.  Then I reversed it, I put the light in the port then looked through the spark plug hole to ensure aspect angle wasn't influencing how soon I saw the light and I got the same numbers.

   If you're curious raising the transfers by 5° equalled roughly .040 of material removed.  So I got back to factory timing plus a little more as you suggested in an earlier post.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 10:38:43 AM
Here's the tac reading after my final tune, it hit 12.1K on some cuts.  This is the last reading I recorded.

(https://forestryforum.com/gallery/albums/userpics/40531/20160228_091042.jpg)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 28, 2016, 10:40:06 AM
My vote is leave it. Raise the exhaust might move your power band up theoretically but at the expense of a little torque. Run it for a bit to see how it is living with that mod for real.  Always wondered about those saws with their longer/taller piston on the same crank & bearing setup designed for the original 372's. Don't think RPM's are your friend with those saws in a typical work application. My humble opinion. And how much work was done to bro's xpw?? My blend using a stock xpw top end runs stronger than my x-torq by quite a bit. Granted its a no base gasket build but that shouldn't be an earth shattering change. So it seems the XPW starts out at a better place... remove similar amounts of metal from strategically defined places and you should end up with a stronger saw maybe??? Even matching the tweaked XPW with your X-torq build would be a win in my book. Of course now the prices have dropped on the old style 50mm top ends... kind of changes things for me.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 10:40:54 AM
Here's what my plug looks like tuned to 12k in the cut.

(https://forestryforum.com/gallery/albums/userpics/40531/20160228_091134.jpg)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 11:03:35 AM
Quote from: weimedog on February 28, 2016, 10:40:06 AM
My vote is leave it. Raise the exhaust might move your power band up theoretically but at the expense of a little torque. Run it for a bit to see how it is living with that mod for real.  Always wondered about those saws with their longer/taller piston on the same crank & bearing setup designed for the original 372's. Don't think RPM's are your friend with those saws in a typical work application. My humble opinion. And how much work was done to bro's xpw?? My blend using a stock xpw top end runs stronger than my x-torq by quite a bit. Granted its a no base gasket build but that shouldn't be an earth shattering change. So it seems the XPW starts out at a better place... remove similar amounts of metal from strategically defined places and you should end up with a stronger saw maybe??? Even matching the tweaked XPW with your X-torq build would be a win in my book. Of course now the prices have dropped on the old style 50mm top ends... kind of changes things for me.

Sound advice.  I'm very happy and I think I will let her be.  I dont want to give up compression gained with the gasket delete.  Compression is torque and it feels good to me right now.
  The only thing I'm considering is putting the carb divider back in to see if it will strengthen the low pressure signal and supply a little more fuel.  Just a curiosity.

   Joes XPW is far from stock : muffler mod, base gasket delete, lower transfers cleaned up, widened exhaust and raised transfers.  He did his port work yesterday.  We've gone through all these mods together for the most part. His saw has an attitude problem...lol
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 28, 2016, 11:21:59 AM
Your going to have a hard time matching that saw I'm afraid.. :) If you do you've done something right! Putting that divider in will certainly change things. One half crosses the jets and the other does not. So you would think the characteristics would change as you would have to have enough fuel in the half exposed to the jets to mix with the air flowing thru the opposite side....and now mix further down stream. Be curious what that does...hard to predict. One thing it will do is add cross sectional area as an obstruction by some small amount.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 11:46:40 AM
Quote from: weimedog on February 28, 2016, 11:21:59 AM
Your going to have a hard time matching that saw I'm afraid.. :) If you do you've done something right! Putting that divider in will certainly change things. One half crosses the jets and the other does not. So you would think the characteristics would change as you would have to have enough fuel in the half exposed to the jets to mix with the air flowing thru the opposite side....and now mix further down stream. Be curious what that does...hard to predict. One thing it will do is add cross sectional area as an obstruction by some small amount.

You're right about that for sure!  I think my false hope came from running both saws in stock form, they felt very close if not identical torque wise.  Hats off to the big bore, wow she runs.

    You bring up all points in consideration for the divider.  That's why I'm curious about putting it back in.  Hands down the saw is getting more flow with all other strato dividers removed so I'm wondering if having the divider in place with the increased volume would draw more fuel out of the jet.  I won't be getting to it today, heck  I'll just save that for our GTG.  Curious to see how mine runs against yours and Spike60s builds.  Of course I did depart from the simple mods and gave it a woods port.  Hopefully the increase isn't all in my head...lol.  But I don't think the tach is lying to me.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 28, 2016, 11:53:23 AM
I prolly won't get to an x-torq build for a while. Still focused on the 562's and having both a learning experience and fun with them.. BUT when they are done, going to start with that Huztl top end first...should be fun AND you folks will have done much of the development! :)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 12:55:46 PM
Quote from: weimedog on February 28, 2016, 11:53:23 AM
I prolly won't get to an x-torq build for a while. Still focused on the 562's and having both a learning experience and fun with them.. BUT when they are done, going to start with that Huztl top end first...should be fun AND you folks will have done much of the development! :)

Glad to here all my attention given to my 372 is still helpful in your 562 experimentation.  I'm excited to see what you come up with.  But then I'll want a 562!  Lol
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 04:30:25 PM
Before:
https://youtu.be/KdTJOJfS9do
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on February 28, 2016, 04:32:12 PM
After:  on the same log as previous video, but we started at the butt end.
https://youtu.be/3C1-sbNGx-o
Title: Re: 372XP X-Torq Modding Final Result
Post by: RIDE-RED 350r on February 28, 2016, 08:00:53 PM
I don't want to jack up this XT thread with my XPW stuff, but I will say that we both made significant improvements to those 372s!  8)

Mine still needs to be tuned in a little more, it 4-strokes in the cut here and there. But even doing that it's spooling 13.6k no load and 11.8k+ in the cut (I swapped in a black unlimited coil from my 359 project). Really happy with how it turned out!
Title: Re: 372XP X-Torq Modding Final Result
Post by: XP_Slinger on February 28, 2016, 08:15:18 PM
XPWs welcome big bro!  I'm just excited about the gains we both produced in our saws!  Not too shabby for our first time actually porting a cylinder.  Glad there's sites like this one and others where experience is shared for the benefit of others.
Title: Re: 372XP X-Torq Modding Final Result
Post by: ehp on February 28, 2016, 08:46:03 PM
Your very safe on jetting, I run a lot leaner than that and that saw  is on its second winter of cutting . Raising your ext port timing doesnot hurt the torque , what it does it make your powerband smaller but raises the hp , So say your powerband right now is 1500 rpms , with a higher ext port timing it may only be 1200 rpms and depends on how much you raise it but will cut faster , If you raise to much then the saw will have no grunt unless you change to a different type of fuel say like E85 or E98 once you get enough fuel to it . . There are a lot of things you can still change and make more power , You made the ext port wider , how much wider ? That one is a big thing same as did you make the transfers wider and if so how much and which end got how much wider , Your ext port ,what kind of shape did you grind into it when you opened that part of the cylinder heading towards the muffler and how smooth did you polish the port . What air filter are you running on the saw , that one may seem stupid but some of these newer flauk filters cut down bad on how much air can go threw them, I'm running mess types . Your not going to port a XT saw in the same time as say a XPW, you just have to spend more time doing little things . The XPW has 4 transfer ports where the XT only has 2 true ports so you need to figure out how to move a lot more air threw those 2 small ports . All these new design of motors need a lot more thinking in them to make good power out of them but it can be done and they last . Your learning and that is what I think counts . You did things and seen how and what it did to the power . If you look around not many saw builders will touch the XT mainly cause what they do doesnot work on these motors so these motors get a bad name but the truth is these are very good motors once straighten out .
Title: Re: 372XP X-Torq Modding Final Result
Post by: RIDE-RED 350r on February 28, 2016, 09:26:26 PM
Neither of us widened the transfers because we are concerned with killing the velocity of the fuel/air charge transferring into the cylinder. We just raised them a few degrees.

Now I have seen it said that a good mod to the exhaust is to widen it to 65-70% of bore diameter. My bore being 51.4mm translated to a port width of 35.98mm being 70%. Stock width was 29.5x mm. I opted not to go right to the 70% measurement of 36mm ad took it to 35mm. I replicated the stock shape of the port ends with my modification. I also blended and enlarged the entire exhaust tract all the way to the muffler mounting flange. And I did remember to match the gasket, heat shield and muffler to the newly enlarged outlet.

Neither of us altered the intake port and opted to leave intake timing as it has been changed by the base gasket delete.

I'm starting to have a renewed interest in raising my exhaust a few degrees after reading your post EHP. :)

We are both running the OEM high top STD filters.

Here is my XPW
https://www.youtube.com/watch?v=I5oGwq_O6aY
Title: Re: 372XP X-Torq Modding Final Result
Post by: ehp on February 29, 2016, 12:43:48 PM
both saws are rich in the videos . I widen the transfer ports more on the XT than the XPW as it has a lot more port area stock , You are correct on thinking about not slowing the air charge down but you need to move enough air/fuel volume to make power and the XT needs this . With the porting numbers if you are sure they are correct , First I would not raise the transfers any more , that's plenty high enough but would widen them and make sure you widen back in by the covers so no restriction for air/fuel flow and blend in on bottom of cylinder so clean flow from out of crankcase . Ext port I would raise but not a lot 3 or 4 degrees and widen to 66 % of port width, 70 % is ok but you need to put good radius on the upper corners so not to hook a ring, same width transfer ports , make sure nice round corners so no ring hooking
Title: Re: 372XP X-Torq Modding Final Result
Post by: XP_Slinger on February 29, 2016, 06:06:10 PM
Good evening ehp.  Thanks for your posts.  As joe stated I didn't widen my transfers but I did work on the entire area behind the cover.  I didn't alter the cover much, just smoothed out rough areas I could see.  Especially on the deflector portions that merge with other contours on the cylinder.  I widened my exhaust about an 1/8" total.  This was an experiment for me to establish a base line of good vs bad width.  I radiused the upper corners to make a continuous contour from the bottom to the top of the port then aplied a good chamfer to all edges.
    Thanks very much for sharing your suggestions on exhaust raising and transfer widening.  When I get into it again I will measure port timing as you described to make sure my numbers are good then I'll go from there.  I am admittedly hesitant to go further with this saw because I really like how it's running, but knowing there are more gains to be had I will probably open it up again.  I'm finding that any amount of success I have in porting saws is addictive and makes me want to try more things like you've suggested to unleash further gains. 
Title: Re: 372XP X-Torq Modding Final Result
Post by: RIDE-RED 350r on February 29, 2016, 06:52:39 PM
Quote from: XP_Slinger on February 29, 2016, 06:06:10 PM
Good evening ehp.  Thanks for your posts.  As joe stated I didn't widen my transfers but I did work on the entire area behind the cover.  I didn't alter the cover much, just smoothed out rough areas I could see.  Especially on the deflector portions that merge with other contours on the cylinder.  I widened my exhaust about an 1/8" total.  This was an experiment for me to establish a base line of good vs bad width.  I radiused the upper corners to make a continuous contour from the bottom to the top of the port then aplied a good chamfer to all edges.
    Thanks very much for sharing your suggestions on exhaust raising and transfer widening.  When I get into it again I will measure port timing as you described to make sure my numbers are good then I'll go from there.  I am admittedly hesitant to go further with this saw because I really like how it's running, but knowing there are more gains to be had I will probably open it up again.  I'm finding that any amount of success I have in porting saws is addictive and makes me want to try more things like you've suggested to unleash further gains.

Goes double for me!!

I'm considering going 2 more degrees on the transfers and raising the exhaust 3 on the Dubya, based on some numbers I have seen posted for it.

Again, not to divert this XT thread into an XPW thread, but any thoughts on whether or not I should do anything with my intake on that XPW?? The only change to it is due to the base gasket delete. I'm wondering if it might benefit from trimming .020-.030 from the piston skirt now due to the changes made to the porting?? But I understand how critical it is not to take the intake too far...

Another J&J's Braapp Shack GTG this weekend Josh?? ;)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 01, 2016, 06:09:07 AM
If I mess with my intake, I was thinking of raising it a bit.  Rather than trimming the skirt and having it close later.  All depends on how far the skirt travels past the top of the port. 
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 01, 2016, 08:21:56 AM
I never trim piston skirt , In my books that is a big no no . You want as much piston skirt as possible to help the intake skirt from wearing caused by the intake port . I always raise the intake roof to match bottom of piston skirt at TDC, No use having port timing that's doing nothing as port is not truly open . XP check how wide you made the ports as the XT has a lot of metal that can be removed
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 01, 2016, 10:28:01 AM
ehp,

    Thanks for the response.  I will definitely go after the intake to piston skirt gap at TDC, I'm glad I wasn't off on my thinking, I just couldn't see the benefit of making the intake close later.  I have to work Saturday but I might get into my saw again on Sunday.  If I do, I'll post some port measurements and timing numbers using your degree method. :P 
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 03, 2016, 07:15:06 PM
Just found this in my phone.  Apparently I did take a pic of the exhaust after widening it.
(https://forestryforum.com/gallery/albums/userpics/40531/20160227_154826.jpg)
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on March 04, 2016, 06:14:23 AM
This is one of the most useful and enjoyable threads I've seen in years on any of these sites. Real good job guys. We're all learning a lot here, except for Ed who's doing most of the teaching.  :)

Did we reach a consensus on the carb divider in or out yet? I'll try and get my 2166 into the woods this weekend. I've got two carbs and can try them both to see what differences I notice.
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 04, 2016, 11:13:21 AM
Quote from: Spike60 on March 04, 2016, 06:14:23 AM
This is one of the most useful and enjoyable threads I've seen in years on any of these sites. Real good job guys. We're all learning a lot here, except for Ed who's doing most of the teaching.  :)

Did we reach a consensus on the carb divider in or out yet? I'll try and get my 2166 into the woods this weekend. I've got two carbs and can try them both to see what differences I notice.

  I agree very enjoyable thread. My 365xt is much better with out the divider. I also like the ignition advance. The ingnition may have helped power but it really helped starting.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 04, 2016, 11:58:50 AM
Quote from: Spike60 on March 04, 2016, 06:14:23 AM
This is one of the most useful and enjoyable threads I've seen in years on any of these sites. Real good job guys. We're all learning a lot here, except for Ed who's doing most of the teaching.  :)

Did we reach a consensus on the carb divider in or out yet? I'll try and get my 2166 into the woods this weekend. I've got two carbs and can try them both to see what differences I notice.

   Glad you're enjoying it Spike.  Were it not for ehp and yourself it would have never happened, I've said it many times but I'll say it again, thank you.

   I haven't had a chance to get back into my saw to test the carb divider theory.  Before I do, I am going to raise my exhaust and intake a couple degrees as discussed in previous posts.  Once I have tuned and cut after this final port "tweak", I'll test the carb divider theory.  I probably won't get to it until Sunday (6 Mar) because I have to work Saturday >:(
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on March 04, 2016, 03:25:16 PM
OH and speaking of timing advance, I think Josh and I both forgot to mention that we both advanced the timing a pinch on our saws as well...
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 04, 2016, 05:45:34 PM
Just went back and reviewed my posts.  I did mention the timing was advanced by about 1/4 width of the key. 
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 05, 2016, 05:16:48 PM
You can port more on the bottom of your cylinder and polish it better , If I get one of my saws a part I will put a picture of a cylinder here to show you . I got a different cylinder here to that I think I'm going to port that is for the xt
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 05, 2016, 08:15:23 PM
Quote from: ehp on March 05, 2016, 05:16:48 PM
You can port more on the bottom of your cylinder and polish it better , If I get one of my saws a part I will put a picture of a cylinder here to show you . I got a different cylinder here to that I think I'm going to port that is for the xt

A picture would be very helpful and generous, thank you.

When you said I can port more on the bottom of the cylinder are you referring to the lower transfers?  I assume so, just want to be sure I'm on the same page with you.
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 05, 2016, 08:21:24 PM
yes the lower transfers , you got a pretty sharp angle where you matched the cylinder to the gasket, that will cause restriction of air flow plus I can see unported casting in the cylinder towards where the door bolts on the cylinder . Open that up, the XT needs more port area . If you watch you can port pretty close to where the 4 screws that hold the door on the cylinder screw into the cylinder , I also grind the cylinder transfer port area to gain port area
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 06, 2016, 06:06:55 AM
Quote from: ehp on March 05, 2016, 08:21:24 PM
yes the lower transfers , you got a pretty sharp angle where you matched the cylinder to the gasket, that will cause restriction of air flow plus I can see unported casting in the cylinder towards where the door bolts on the cylinder . Open that up, the XT needs more port area . If you watch you can port pretty close to where the 4 screws that hold the door on the cylinder screw into the cylinder , I also grind the cylinder transfer port area to gain port area

Thanks for the advice.  The lower transfers were my first grinding venture on the cylinder and I went at them with 2 concerns in mind: transfer cover screws and velocity.  With these in mind, I shaped them as you see to create a better "funnel" for the charge coming out of the crank case.  I will re-attack the lowers along with the intake and exhaust  as you have advised when I get it on the bench again.  I'm also going to widen the transfers toward the intake by about .030.   Unfortunately it probably won't be today as I previously stated, it's my wife's birthday and I don't think spending 3 to 4 hours at the bench would be conducive to maintaining peace on the home front...lol.  As things sit now, I have to do a brake job on one of our vehicles so my barn time will be occupied by necessity.
   More to follow and thanks for sharing Ed.
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 06, 2016, 09:58:00 AM
"I don't think spending 3 to 4 hours at the bench would be conducive to maintaining peace on the home front...lol. "

  Another way to look at it is, go ahead and spend the day porting ya can't make a women happy anyway. ::) Well no, better not listen to me. :-X
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 07, 2016, 05:55:40 AM
Quote from: 49er on March 06, 2016, 09:58:00 AM
"I don't think spending 3 to 4 hours at the bench would be conducive to maintaining peace on the home front...lol. "

  Another way to look at it is, go ahead and spend the day porting ya can't make a women happy anyway. ::) Well no, better not listen to me. :-X

Definitely won't be following that advice. ..lol!
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 07, 2016, 03:46:42 PM
Well, I got a new project and I felt it necessary to let you guys know that I won't be working on my saw for a couple weeks.  I WILL get back to it to finish up the porting, but for now I'll be wrenching on this 90' Blazer to get it up to par for daily driving. 8)

(https://forestryforum.com/gallery/albums/userpics/40531/BlazerRt.jpg)
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 07, 2016, 10:05:22 PM
I got one of those, same color. But yours looks to be in much better shape than mine.
Title: Re: 372XP X-Torq Modding
Post by: Sawmill Man on March 08, 2016, 08:44:37 AM
Ok now lets get the heads off that blazer and get to work on them .
Title: Re: 372XP X-Torq Modding
Post by: weimedog on March 08, 2016, 10:00:43 AM
Quote from: XP_Slinger on March 07, 2016, 03:46:42 PM
Well, I got a new project and I felt it necessary to let you guys know that I won't be working on my saw for a couple weeks.  I WILL get back to it to finish up the porting, but for now I'll be wrenching on this 90' Blazer to get it up to par for daily driving. 8)

(https://forestryforum.com/gallery/albums/userpics/40531/BlazerRt.jpg)

Perfect saw carrier! Small Block? When I was a kid my dad had one of that configuration.  What an awesome truck it was. What a great vehicle to take the girl friend for trips crawling around the rocky and steep dirt trails on the Power lines doing things kids do. Lot of memories in those trucks. Fishing, Firewood scavenging, dragging dirt bikes to the races....
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 08, 2016, 10:44:12 AM
Quote from: weimedog on March 08, 2016, 10:00:43 AM
Quote from: XP_Slinger on March 07, 2016, 03:46:42 PM
Well, I got a new project and I felt it necessary to let you guys know that I won't be working on my saw for a couple weeks.  I WILL get back to it to finish up the porting, but for now I'll be wrenching on this 90' Blazer to get it up to par for daily driving. 8)

(https://forestryforum.com/gallery/albums/userpics/40531/BlazerRt.jpg)

Perfect saw carrier! Small Block? When I was a kid my dad had one of that configuration.  What an awesome truck it was. What a great vehicle to take the girl friend for trips crawling around the rocky and steep dirt trails on the Power lines doing things kids do. Lot of memories in those trucks. Fishing, Firewood scavenging, dragging dirt bikes to the races....

Lots of blazer memories for me too.  Red and I grew up riding around in our parents 76' K5.  This one that I am getting has a TBI 350 in it.  Runs nice too, should get between 16 and 18 mpg.
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on March 09, 2016, 10:36:24 AM
All of those short wheelbase full size rigs were great trucks, back when they were supposed to actually be trucks. The Ramcharger and Bronco along with the GM twins.

Well, we're off topic aren't we?  :D
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 09, 2016, 04:02:12 PM
Quote from: Spike60 on March 09, 2016, 10:36:24 AM
All of those short wheelbase full size rigs were great trucks, back when they were supposed to actually be trucks. The Ramcharger and Bronco along with the GM twins.

Well, we're off topic aren't we?  :D

We sure are!  But I'll talk about square body Chevys, Fords and Dodges anywhere, they're all good IMO. ..lol

I'll get back to the saw, just gotta get some other stuff sorted out.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 12, 2016, 06:17:39 AM
Well the blazer deal fell through...for now.  Seller didn't have a title with his name on it, I'm an over paranoid kind of fellar when it comes to stuff like that being on the level.  It may still happen in 3 to 4 weeks when he gets the title.

    Back to the saw.  I'm saying this again and it may change but I'm going to leave my saw intact for a while.  I have to get my firewood done before the boats come out of storage and if I keep playing with my saws I'll be doing firewood in August...again.  I know I'm leaving some power on the table for now but I'll get back to it, maybe at our GTG that should be happening soon.  Of course once Joe sees this post he might come to the barn and hit me with a board and tell me to tear it down and finish the porting.  Lol!  Time will tell. 

   Since we were off topic, I put some new rubber on my 85 last night...now I want a 3" lift.
(https://forestryforum.com/gallery/albums/userpics/40531/20160311_191324.jpg)
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 19, 2016, 08:11:24 PM
put the tach on mine today cutting the the bush falling timber , saw powerband was at 12,700 rpms . If I did not push on it pretty hard it stayed on the coil limiter . Running a 24 inch bar and rackers cut good and low to cut this ash with EAB and white oak
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 20, 2016, 10:21:51 AM
I did some port work on my 365xt last week.
Starting duration numbers after base gasket delete were:
    Ex.156=102 ATDC
    Int.147=73 BTDC
    Xfr.125=117.5 ATDC
    Bd.15.5
After duration numbers were:
     Ex.161=99.5 ATDC
     Int.158=79 BTDC
     Xfr.125=117ATDC
     Bd.18
I did not widen the exhaust much or raise the transfer ports. I wanted to stay conservative.
(https://forestryforum.com/gallery/albums/userpics/40721/015~0.JPG)
(https://forestryforum.com/gallery/albums/userpics/40721/019~0.JPG)
The lower corners of these covers seemed to be a restriction after I squared up the transfer opening in the bottom of the jug. Next photo.
(https://forestryforum.com/gallery/albums/userpics/40721/023.JPG)
(https://forestryforum.com/gallery/albums/userpics/40721/022~1.JPG)
I didn't take much off the lower tranfers, the theory being it increases crankcase volume.
(https://forestryforum.com/gallery/albums/userpics/40721/025.JPG)
This seems odd to me. The piston blocks a large portion of the transfer port at bottom dead center.
(https://forestryforum.com/gallery/albums/userpics/40721/008.JPG)

   I am very happy with the results. I tested the saw in 24 inch ash I have up at the barn and it has gained about 1000 rpms over my other mods. I believe it is hitting the rev limiter in the cut because the tack goes goofy. I am going to try my black unlimited coil and see if it does the same thing.
   If I can get a camera man, I want to video this saw and my stock, except for muffler mod, 2188 in the same wood, bar and chain.
   Looking forward to comments good and bad.
   
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 20, 2016, 05:14:07 PM
Your running pretty much stock ext port numbers , I do a lot more porting than what I see you guys doing and that's all over the cylinder and piston. You removed the base gasket so that is going to push the piston farther into the cylinder bore at BDC, you guys are correct about worrying about crankcase volume and pressure but do the volume of the old 4 port transfer 372 xp then measure the XT. the xt is a lot smaller so you can remove lots before you remove to much
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 21, 2016, 10:19:14 AM
Quote from: ehp on March 20, 2016, 05:14:07 PM
Your running pretty much stock ext port numbers , I do a lot more porting than what I see you guys doing and that's all over the cylinder and piston. You removed the base gasket so that is going to push the piston farther into the cylinder bore at BDC, you guys are correct about worrying about crankcase volume and pressure but do the volume of the old 4 port transfer 372 xp then measure the XT. the xt is a lot smaller so you can remove lots before you remove to much
We are timed. ;D
My compression is now back to what it was stock. 182 psi.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 21, 2016, 01:59:47 PM
Quote from: 49er on March 21, 2016, 10:19:14 AM
Quote from: ehp on March 20, 2016, 05:14:07 PM
Your running pretty much stock ext port numbers , I do a lot more porting than what I see you guys doing and that's all over the cylinder and piston. You removed the base gasket so that is going to push the piston farther into the cylinder bore at BDC, you guys are correct about worrying about crankcase volume and pressure but do the volume of the old 4 port transfer 372 xp then measure the XT. the xt is a lot smaller so you can remove lots before you remove to much
We are timed. ;D
My compression is now back to what it was stock. 182 psi.

Nice work Niner.  Your saw had 182psi stock?  Mine was only 150psi before I deleted the gasket and it pumped up to 180psi after the delete.  Haven't gotten back into mine to finish the exhaust and intake yet, I've been working my 357XP on a log pile and now I'm swinging the old hickory handled wood splitter.  Gotta get my wood done before the boat comes out of storage!
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 21, 2016, 08:30:18 PM
Good for you XP, hydraulic splitters  are for sissies.
My compression was 200 before I raised the exhaust.
Title: Re: 372XP X-Torq Modding
Post by: Andyshine77 on March 22, 2016, 04:35:25 AM
Ed has you guys on the right track, "as he always does" ;) the transfers on the 372XT are much smaller than the old quad transfer saws. I am somewhat conservative when it comes to opening up the transfer tunnels on the quad transfers, but you should be able to hog out the XT transfers tunnels pretty good. Playing with the strato timing can really effect how the saw runs, more air/fuel in the combustion is a good thing. :) 

When it comes to compression I like to stay around 170psi to 180psi on the 372, the bottom end with thank you. Many manufactures use sealant theses days, and like most I've never had an issue. In fact I have to use considerable force to separate the cylinder from the case. IMHO if you have issues with the base sealing, you have other issues at play, like poor machining of the base. I've seen poor machining from more than one well respected saw builder, chatter, deep groves, being out more than .010" from corner and so on.

         
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 22, 2016, 05:59:34 AM
Quote from: Andyshine77 on March 22, 2016, 04:35:25 AM
Ed has you guys on the right track, "as he always does" ;) the transfers on the 372XT are much smaller than the old quad transfer saws. I am somewhat conservative when it comes to opening up the transfer tunnels on the quad transfers, but you should be able to hog out the XT transfers tunnels pretty good. Playing with the strato timing can really effect how the saw runs, more air/fuel in the combustion is a good thing. :) 

When it comes to compression I like to stay around 170psi to 180psi on the 372, the bottom end with think you. Many manufactures use sealant theses days, and like most I've never had an issue. In fact I have to use considerable force to separate the cylinder from the case. IMHO if you have issues with the base sealing, you have other issues at play, like poor machining of the base. I've seen poor machining from more than one well respected saw builder, chatter, deep groves, being out more than .010" from corner and so on.

       

Excellent point about the base and crank case being "true" when using sealants.  I had to trim a piece of protruding crank case gasket on my saw when I deleted my gasket.  Had I not done that I would have likely had a leak, it may have leaked some with the gasket.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 22, 2016, 06:01:08 AM
Quote from: 49er on March 21, 2016, 08:30:18 PM
Good for you XP, hydraulic splitters  are for sissies.
My compression was 200 before I raised the exhaust.

What is your squish measurement?  200 psi seems high to me.  Maybe I'm wrong, just curious...thanks
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 22, 2016, 05:04:01 PM
Quote from: XP_Slinger on March 22, 2016, 06:01:08 AM
Quote from: 49er on March 21, 2016, 08:30:18 PM
Good for you XP, hydraulic splitters  are for sissies.
My compression was 200 before I raised the exhaust.

What is your squish measurement?  200 psi seems high to me.  Maybe I'm wrong, just curious...thanks

Squish is .020. When new compression was 180 psi. Now it is at 182 psi.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 22, 2016, 05:15:59 PM
Quote from: ehp on March 20, 2016, 05:14:07 PM
Your running pretty much stock ext port numbers , I do a lot more porting than what I see you guys doing and that's all over the cylinder and piston. You removed the base gasket so that is going to push the piston farther into the cylinder bore at BDC, you guys are correct about worrying about crankcase volume and pressure but do the volume of the old 4 port transfer 372 xp then measure the XT. the xt is a lot smaller so you can remove lots before you remove to much

Thanks for the guidance Ed.  I red your post about your saw running 12.7k in the cut if you lean on it.  Woof!  Mine isn't that strong yet...baby steps.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 22, 2016, 05:17:58 PM
Quote from: 49er on March 22, 2016, 05:04:01 PM
Quote from: XP_Slinger on March 22, 2016, 06:01:08 AM
Quote from: 49er on March 21, 2016, 08:30:18 PM
Good for you XP, hydraulic splitters  are for sissies.
My compression was 200 before I raised the exhaust.

What is your squish measurement?  200 psi seems high to me.  Maybe I'm wrong, just curious...thanks

Squish is .020. When new compression was 180 psi. Now it is at 182 psi.

If I remember correctly my squish is .024.  Can't imagine .004 making a 20 psi difference but every saw is different.  Can't wait to see a video of your saw in action.
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 24, 2016, 02:33:09 PM
Not sure if I would want a black coil in my 365/372 xts , they hit the limiter real hard so guessing with the black coil I would be in the 15,000 to 16,000 rpm range out of the wood
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 24, 2016, 02:35:01 PM
I'm about 175 psi when I built this last one , not sure now after its cut hard for 8 months
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 25, 2016, 07:47:46 AM
Quote from: ehp on March 24, 2016, 02:33:09 PM
Not sure if I would want a black coil in my 365/372 xts , they hit the limiter real hard so guessing with the black coil I would be in the 15,000 to 16,000 rpm range out of the wood

I'm sticking with the limited coil in my saw also.  Granted, being able to tune it under no load is easier but I wouldn't want to spin my saw up to the 15k range because of the heavier piston.  I'll just stick to tuning it in the cut, the more I do it the easier it becomes.
    Once I get the intake put back on my old Chevy I might find the time to get back into my XT to widen the transfers and raise the exhaust a bit.  The forecast is looking favorable for a day in the barn.
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 25, 2016, 11:12:35 AM
My concern with the blue limited coil is, if you are close to the rev limiter in the cut and lift the saw to listen for "4-stroke" how do you know if it is "4-stroke" or the limiter? Ya could try to watch the tack but things happen fast. At least with a black coil ya know what is causing the 4-stroke sound.
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 25, 2016, 11:56:20 AM
My old Jimmy.
(https://forestryforum.com/gallery/albums/userpics/40721/007.JPG)
My old old Blazer.
(https://forestryforum.com/gallery/albums/userpics/40721/010~1.JPG)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 25, 2016, 03:22:32 PM
Quote from: 49er on March 25, 2016, 11:12:35 AM
My concern with the blue limited coil is, if you are close to the rev limiter in the cut and lift the saw to listen for "4-stroke" how do you know if it is "4-stroke" or the limiter? Ya could try to watch the tack but things happen fast. At least with a black coil ya know what is causing the 4-stroke sound.

I use a tach to tune in the cut, after a few cuts I pull the plug to verify I'm not too lean.

Nice truck!
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 25, 2016, 03:31:31 PM
Quote from: XP_Slinger on March 25, 2016, 03:22:32 PM
Quote from: 49er on March 25, 2016, 11:12:35 AM
My concern with the blue limited coil is, if you are close to the rev limiter in the cut and lift the saw to listen for "4-stroke" how do you know if it is "4-stroke" or the limiter? Ya could try to watch the tack but things happen fast. At least with a black coil ya know what is causing the 4-stroke sound.

I use a tach to tune in the cut, after a few cuts I pull the plug to verify I'm not too lean.

Nice truck!
Yes, three more payments and it's all mine.

You realize to properly read a plug requires special optics to see the porcelain at the very bottom. It can't be done without them. The part ya see with the naked eye don't mean much.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 25, 2016, 08:28:53 PM
Quote from: 49er on March 25, 2016, 03:31:31 PM
Quote from: XP_Slinger on March 25, 2016, 03:22:32 PM
Quote from: 49er on March 25, 2016, 11:12:35 AM
My concern with the blue limited coil is, if you are close to the rev limiter in the cut and lift the saw to listen for "4-stroke" how do you know if it is "4-stroke" or the limiter? Ya could try to watch the tack but things happen fast. At least with a black coil ya know what is causing the 4-stroke sound.

I use a tach to tune in the cut, after a few cuts I pull the plug to verify I'm not too lean.

Nice truck!
Yes, three more payments and it's all mine.

You realize to properly read a plug requires special optics to see the porcelain at the very bottom. It can't be done without them. The part ya see with the naked eye don't mean much.

I respectfully disagree.  Black is rich, white or clean is lean, grey is pushing it, tan is good to go.  Are there more accurate ways of doing it with special equipment?  Absolutely.  But plug visuals have never let me down in all my years of playing with 2 strokes and 4 strokes alike.  A good LED bore light will give you a good look at the base of the insulator.
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 26, 2016, 10:03:33 AM
Ah, we disagree, no big deal. 8)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 26, 2016, 05:06:28 PM
It was bound to happen eventually...lol
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 26, 2016, 08:14:28 PM
well yes and no , yes you can have a black colour sparkplug and be lean, With a small hole in your muffler like a stock chainsaw and in very lean conditions you can get a very glossy black colour sparkplug , small hole in the muffler helps hold the heat in and with the small hole the motor will still run just not proper . Reading sparkplug in a chainsaw is not like reading a sparkplug out of a snowmobile or a 2 stroke dirtbike as they both have a lot more help getting rid of the engine heat as most are liquid cool motors . Chainsaw is air cool and relieves a lot more on the gas/oil to help keep the engine from burning up so sparkplug colour is going to be different . You take a plug out of my motors I use everyday and their a light tan colour
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 26, 2016, 08:35:02 PM
Agreed.  I disagree with Niner with regard to a visual plug read being useless.  Tan is where I want to be, even if that means leaving a little power untapped.
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 27, 2016, 12:40:51 PM
Quote from: XP_Slinger on March 26, 2016, 08:35:02 PM
Agreed.  I disagree with Niner with regard to a visual plug read being useless.  Tan is where I want to be, even if that means leaving a little power untapped.
I did not mean to say it is useless, however it is not a reliable way to tune.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 27, 2016, 05:30:47 PM
Quote from: 49er on March 27, 2016, 12:40:51 PM
Quote from: XP_Slinger on March 26, 2016, 08:35:02 PM
Agreed.  I disagree with Niner with regard to a visual plug read being useless.  Tan is where I want to be, even if that means leaving a little power untapped.
I did not mean to say it is useless, however it is not a reliable way to tune.

Copy all
Title: Re: 372XP X-Torq Modding
Post by: weimedog on March 27, 2016, 06:05:54 PM
Kind of late to the party...haven't been building the 372's I've SUPPOSED to have been for a couple of weeks. Went off to goofy old saws and still on the 562's. Learned a LOT about those 562's and have updated some of what I've learned here through some trial and error...that will bleed out into videos over this next year or so. No rush. Some interesting stuff happening in the 562 world...so things will have to settle some before I chat about it.

But to plug checking. In the motorcycle world you checked the Water Cooled same as the older Air Cooled. Looked for that "tan" color and if it was white or even worse grey, start looking for melted pistons....didn't matter air or water cooled. The problem with using plug color is it takes time for it to develop. Its one of those things you do after a days work or at least a half day AFTER tuning with a tach or if your old school a well tuned "ear". Or in the motorcycle world after a practice session and certainly after a Moto. It still is something I do as much for verification as it is really trying to improve the "tune". here's the thing. Every one runs their saws different. I couldn't care less what the experts say, folks all are a little different. How hard they push, chain sharpness, the RPM they think is the sweet spot, the actual tune of the saw, the oil mix, how clean the saw is..it goes on and on. So the best way to deal with OTHER folks saws is using a tach and manufactures specs. A great starting point. Then on your saws...the color of the plug will allow you to tweak a bit based on the conditions YOU are running on a particular day .. or even season. THEN the temps change or the wood changes and plug checks are a way to follow the conditions with empirical data about your saw. For most, its a waste of time. I do it still. Habits from the old racing world. And it does pay off from time to time. It's not like I pull the plug every day after I get the "tune" where I like it, but if I haven't run the saw for a while, I'll check half day, or if things don't feel right, I'll check the plug. And when I do my initial setup for a new build I track it for a bit. Just me. Been doing the same thing since the 1970's.
Title: Re: 372XP X-Torq Modding
Post by: ehp on March 27, 2016, 09:35:08 PM
the most interesting thing in the 562 world is scrap the autotune or at least do a lot of work to the carbs to make them run proper as they sure donot run proper stock .
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 28, 2016, 11:55:14 AM
Quote from: ehp on March 27, 2016, 09:35:08 PM
the most interesting thing in the 562 world is scrap the autotune or at least do a lot of work to the carbs to make them run proper as they sure donot run proper stock .
Do you have a link or anything I could read up on about the "562 world."
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on March 28, 2016, 04:56:59 PM
Nail on the head Weimdog...

You sacrifice the plug, but if you really want a good look at the entire porcelain just take your trusty hacksaw or whizzy wheel and cut the threads off. Then there is reading the anneal line on the strap, color of the electrode tip. But this is for getting the last bit of fine tuning down which just isn't absolutely necessary for most folks. Whether it's my saw or my 250r, I just want it to run without biffing the plug and make good power without being too close to the ragged edge. I purposely tune most of my toys to be a little on the safe side. I'm not a racer. ;)

Plug chops/reads are not the entire picture, but in most cases for normal use it gets you close enough to make good power safely..I agree that plug reads on saws will be more tricky. With something like my 250r (or pretty much any 2-stroke sled, bike, etc) If I want a snapshot of how it's running on the low/pilot circuit I put a new plug in and ride several minutes, in the same gear if possible without exceeding 1/4 throttle. Same procedure for mid and high only throttle positions are done in accordance to what circuit I want to have a look at. Granted, WOT is pretty difficult as I can't often hit and/or mantain WOT in top gear on my R, that would be running north of 80mph! Idle is set by ear and idle airscrew setting. If not between 1 and 1-3/4 achieves the best idle, I need to make an adjustment to the pilot jet...Anyway, I'm rambling again! LOL! All of that to say this, saws are much more rudimentary in the carb department than a Keihin PWK, mainly because of their intended use and that is to be run at idle or WOT with little if any in-between.

To the extreme end of the spectrum, highly modded purpose built stuff you will be running EGT's, Dial-A-Jet setups, Lectrons with power jets, and all kinds of fun tweeky stuff! LOL!  Most of which is above my paygrade...literally.... I can't afford all of those go-fast goodies! LOL!
Title: Re: 372XP X-Torq Modding
Post by: Andyshine77 on March 28, 2016, 07:38:59 PM
I won't say chainsaw plug reading is useless or impossible, it is however quite difficult, do to the nature of how saws run, with temps all over the place. IE make one long cut, or let the saw idle a little and the plug will change quick. Is it another tool to use when looking for the perfect air fuel mixture? you bet! I personally rely more on other indicators. I've found looking at the exhaust side of the piston a very valuable tool, especially when you really push the saw well past it's original performance envelope. We all have our own ways, if what you're doing woks that's all that matters. 

I have a new 562 headed my way, 8) so I'll see how they run stock. Take into consideration these saws are still evolving and from all accounts have gone through some changes recently, so we'll see.                 
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on March 28, 2016, 07:51:45 PM
Well said Andre...

On the 562, I recently heard from a reliable source that they have changed the cylinders.... Not sure in what way though.
Title: Re: 372XP X-Torq Modding
Post by: Andyshine77 on March 28, 2016, 08:21:17 PM
Quote from: RIDE-RED 350r on March 28, 2016, 07:51:45 PM
Well said Andre...

On the 562, I recently heard from a reliable source that they have changed the cylinders.... Not sure in what way though.

Bob didn't tell me that! lol. He did say the newest saws had a few changes, better air flow over the cylinder sounds like one of them.   
Title: Re: 372XP X-Torq Modding
Post by: weimedog on March 28, 2016, 11:48:57 PM
I heard changes but not specifics. So until the official list of changes are out I won't make any assumptions. Fact is the tweaked 562's I've worked with are 2014 spec and they seem solid. Finished one today. Left the el46 on it and it runs really well. No bog or hesitation. My mods focus as much on cooling as compression. I get all the folks using those saws to run 32:1 as well..:)  Nice tan plugs after test hits as well...:) Changes are inevitable as models go through their life, the one being sold now are *DanG good saws....curious what they have done.
Title: Re: 372XP X-Torq Modding
Post by: Andyshine77 on March 29, 2016, 12:30:11 AM
Only thing Bob said for sure was the newest 562's have an extra cutout in the top cover for added cooling. I have little experience with the 562, other than running two early editions at a gtg, both were quite fickle. I have quite a few standing dead Ash trees to take down in the next few weeks, so I should be pitting some time on the saw. I feed my saws 32:1 as well. A tan plug is what I like to see! :) 

Sorry for turning this into a 562 thread guys. smiley_beertoast
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 29, 2016, 06:21:10 AM
Quote from: Andyshine77 on March 29, 2016, 12:30:11 AM
Only thing Bob said for sure was the newest 562's have an extra cutout in the top cover for added cooling. I have little experience with the 562, other than running two early editions at a gtg, both were quite fickle. I have quite a few standing dead Ash trees to take down in the next few weeks, so I should be pitting some time on the saw. I feed my saws 32:1 as well. A tan plug is what I like to see! :) 

Sorry for turning this into a 562 thread guys. smiley_beertoast

No apology necessary for a good conversation.  Hell, we all started talking trucks for a page...lol
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on March 29, 2016, 03:39:49 PM
Agree on the changes not being clear guys. My source at GKS only stated that Husky made some changes to the cylinders but he stated that he did not know the specifics of the change...

One thing I hope changes for the sake of you 562 owners is that they addressed the broken/damaged transfer cover O-ring issues that I have been reading about from several people.
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 29, 2016, 07:30:27 PM
What broken "O"ring problem. I haven't heard anything.
Title: Re: 372XP X-Torq Modding
Post by: Andyshine77 on March 29, 2016, 11:34:51 PM
I believe the transfer O-ring issue is more 550 related, I don't recall 562's having any issues with them. 
Title: Re: 372XP X-Torq Modding
Post by: 49er on March 30, 2016, 09:48:15 AM
Well, that's good, the bad is I have a 2253.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on March 30, 2016, 03:42:50 PM
Some of the reputable porters on other forums have stated running into this issue on enough saws that it can't be shrugged off as an anomaly. I'm fairly certain that the 562 has been among them.

One thing that was stated is that in many cases, AT was able enough to compensate for it that no symptoms were present when running the saw. These were discovered upon removing the transfer covers for porting.

I wouldn't advise removing the covers just to check if your saws are running fine. Husky has not yet made the O-rings available separately as of last I heard. If you do have issues, it could be the O-rings and it might be worth a look. Believe it or not, one must buy a whole new cylinder to get new O-rings. Stupid, I know!

I would also note that they use "tamper resistant" Torx screws on the covers. So they did not intend for these covers to be removed, generally speaking.

The 372XT also uses transfer covers...

There! I got the conversation back on the 372.. ;)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on March 31, 2016, 06:09:12 AM
Just had a thought.  Anyone ever consider ditching the O-ring in favor of a gasket + 3Bond?  Seems to me that you could increase the transfer runner volume a bit by doing this.  My only reservation would be whether or not the cover is rigid enough to seal properly with a gasket vs the O-ring.  Just thinking out loud...Opinions?
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 03, 2016, 10:51:01 AM
Josh and I are going back into our 372s as we speak to make those final alterations to exhaust and transfer timing. Still considering whether or not to do any work on the intake with mine as I want to be cautious to avoid losing too much intake velocity.

We don't have any test logs today so all we will be able to do is finish the porting and get an initial no-load tune on them. First wood they see will be at the GTG next week! :)

I'll post up our final numbers once we get done today. :)
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 03, 2016, 05:13:45 PM
OK, mission accomplished. :)

I hit my target with my numbers: Ex:100, Trans:122, Int:75. Blowdown being 22.

I also squared the intake but I did not lower the floor at all. Pulling 160psi compression still.

We didn't take any videos due to not having any logs to make cookies with ATM. But I am positive the changes made today were an improvement. I'll post some pics when I get on my laptop.

Really looking forward to the GTG and getting feedback from you guys on how we did.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 03, 2016, 05:33:14 PM
We have some terrible weather today so with a little motivation from joe I got back into my x-torq.  Here's what I got done.

1) Raised the exhaust 3°

2) Widened the transfers by roughly 1/16 of an inch toward the exhaust and removed a lot of material from nearly everywhere in the transfer track to include opening up the lowers more than I already had as Ed suggested.

3) Brought the bridge between the strato ports to an edge and widened the intake on the carb side, not the cylinder window.
***A word of caution to other readers...be careful if attempting to widen the intake port window in the cylinder.  I almost went at it without looking at the piston design and I'm glad I didn't.  The intake port window is 18mm wide, the skirt on the piston between the strato cut outs is 19.1mm wide.  If I had widened my intake paying no attention to the piston my intake would have been opening into the strato cut outs and the intake/transfer cycle would have been screwed.  Maybe my assumption of these negative effects is wrong but unless I am informed otherwise I won't be widening my intake port window with only .5mm available on each side to ensure the intake stays closed.

  So to summarize my port numbers are now as follows.

Exhaust - 98°
Exhaust Width - 31mm (62% of bore)
Transfer - 117°
Intake - 77°
Compression - 170 psi (180 prior to
                            raising the exhaust)

I also used the port timing method Ed described a couple pages back.  I much prefer using this method compared to what I was doing before because dividing the result by 2 provides a more accurate final number for port opening. And this revealed that my exhaust was opening at 101° not 100°.  A small difference I know, but as we all know the small things matter.

   No wood on my landing means no test cuts today, I'll save that for the GTG next weekend.  Hopefully it cuts as good as it sounds.

Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 03, 2016, 06:00:30 PM
Here are the pics of my work today:

This is the exhaust. I widened it to 35mm which is 70% of bore diameter. I also opened up the entire exhaust outlet, gasket, heat shield, and muffler to match.
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160403_140402245~0.jpg)
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160403_140425432~0.jpg)

A shot of the intake after I squared it up.
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160403_145335563_HDR~1.jpg)

And a general shot of the lower transfers after some addition cleanup
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160403_140527573_HDR~1.jpg)




Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 03, 2016, 07:26:41 PM
That's what I forgot to get; pictures.  Crap
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 03, 2016, 07:48:43 PM
Next up: those  57s that just refuse to fail to impress!! You better get pics when we do those...  8)

Unless of course my 394 gets to the bench first...   :snowball: ;D
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 03, 2016, 09:17:17 PM
Quote from: RIDE-RED 350r on April 03, 2016, 07:48:43 PM
Next up: those  57s that just refuse to fail to impress!! You better get pics when we do those...  8)

Unless of course my 394 gets to the bench first...   :snowball: ;D

My bench, my rules.  Lol!
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 04, 2016, 10:13:41 AM
  My saw is back to the erratic idle. :'(  Here is what it does, Set idle @ about 3k, make a nice long cut in 26inch oak, saw comes out barely running at 2.4k, within ten seconds it is idling @ 3.6k with the chain spinning.
   It is like a air leak somewhere with the oil sealing it after a long cut. But a vacuum and pressure test revealed no leaks. Yesterday, I lowered the popoff pressure from 30psi to around 18-29 psi. The saw runs the same. It is not the tank vent either.
   Today, I am going to install a new nozzle in the carburetor. If I didn't value my hair so much I'd pull it out. >:(  All suggestions are appreciated.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 04, 2016, 11:06:10 AM
Niner,

     Given your symptoms and the fact that an air leak is not present as recorded by your test, I would suspect that your low speed jet is set too lean.  When the saw gets good and hot this lean setting could be amplified.  I would get the saw hot and richen the low speed until your idle is between 2700 & 3000RPM.  Then see how it does.  Hope this helps, but I'm sure you have already tried jetting out the problem.  Are the limiters still on your jets?

Next thing I would check if the jetting is good is the fuel line.
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 04, 2016, 06:43:41 PM
your to lean on the low speed side, so either your jet is to lean or your idle is to high . With the coil that is in these saws if you set the low to lean  or idle screw set to  high of a rpm for idle the coil advances the timing and that causes the saw to raise it rpms , most saws this happens around the 2800 or so rpms . The fuel line in the XT's suck and get a hole in the line where the line goes threw the fuel tank which causes the idle to be all over the place but will run at full throttle
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 04, 2016, 06:46:39 PM
Am thinking 31 mm is better but wider would help on ext port . You got to lean the carb down lots to to make it cut . I'm quite a ways leaner on high speed jet than where the saw hit the coil limiter
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 04, 2016, 06:59:13 PM
Quote from: ehp on April 04, 2016, 06:46:39 PM
Am thinking 31 mm is better but wider would help on ext port . You got to lean the carb down lots to to make it cut . I'm quite a ways leaner on high speed jet than where the saw hit the coil limiter

Yes I agree.  I re-red some things you posted a while back and saw that you recommended 70% of bore for the width, I simply forgot that you shared that information amidst everything else going on around my place.  I'll see how it runs at weimedog s place this Sunday and go from there.

   Do you widen the intake side of the transfers?  I chose to widen toward the exhaust because of the lip that was there as the charge entered the cylinder.

    Thanks for sharing your port timing method, I like it a lot.  What do you think about my final numbers?  In hindsight, I wish I would've left the transfers a little lower.  I remember you saying you don't like to share your numbers but that's not what I'm after.  Just your opinion on where I ended up and possibly some incite as to what I could've done better. 

    Spike is bringing an unlimited coil to our GTG so if all goes well I'll be ditching the limited coil.
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 04, 2016, 08:37:43 PM
I found this today after I pressed in a new jet into the Walbro RWJ-4B
(https://forestryforum.com/gallery/albums/userpics/40721/007~0.JPG)
Which lead to this!
(https://forestryforum.com/gallery/albums/userpics/40721/008~1.JPG)
   The flange had covered the hole so it was not as much of a leak as ya might think. I know EHP if the timing advance kicks in at idle it will play heck with it. I had already switched back to the black unlimited  coil. Because this problem has come and gone over the almost two years I have had the saw I don't think this is the root cause of my problem. But this hole don't help anything.
   Also, the low speed needle just doesn't respond as it should. Right now the saw will idle with the low jet screwed all the way in and not die with it backed all the way out. I may just try a new carburetor. I might be getting a little discussed. Mostly because of self inflicted wounds.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 04, 2016, 08:43:42 PM
Good find Niner.  I hope you get your saw running right again, being frustrated sucks.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 07, 2016, 12:59:29 PM
Ran my 372 a couple days ago.  I left it tuned pretty rich and it still put a smile on my face :).  Throttle response is phenomenal, and it flat out screams.  Very happy happy happy with what I have gained on my rookie porting job.  I'll try to get a video over the next couple days with it tuned properly.  Thanks for all the help ehp, Spike60, 49er, and weimedog!
Title: Re: 372XP X-Torq Modding
Post by: weimedog on April 07, 2016, 02:42:21 PM
Quote from: XP_Slinger on April 07, 2016, 12:59:29 PM
Ran my 372 a couple days ago.  I left it tuned pretty rich and it still put a smile on my face :).  Throttle response is phenomenal, and it flat out screams.  Very happy happy happy with what I have gained on my rookie porting job.  I'll try to get a video over the next couple days with it tuned properly.  Thanks for all the help ehp, Spike60, 49er, and weimedog!

we might be able to help in the video department in a couple of days
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 07, 2016, 03:43:44 PM
Now Josh, you need to tell them what you brought home to look at for Jesse and how it feels compared to your 72... And you were worried that the improvements were just in your head! LOL!
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 07, 2016, 05:31:09 PM
Quote from: RIDE-RED 350r on April 07, 2016, 03:43:44 PM
Now Josh, you need to tell them what you brought home to look at for Jesse and how it feels compared to your 72... And you were worried that the improvements were just in your head! LOL!

   It's not really a fair comparison nor a complete one but ok. 
   A friend asked me to look at his 2166 because it's leaking bar oil.  Naturally I couldn't help but fire it up, the difference in throttle response is night and day between his saw and mine. 
   Onto the bar oil issue.  I discovered that the lube adjuster was turned way out, about 8 full turns from bottomed out.  Didn't seem right to me so I turned it in til it gently bottomed and then brought it out 4 turns.  Does that sound about right to you more experienced saw tweakers? 
   The adjuster was literally wiggling in its bore before I made the adjustment.  Thinking it was too loose for o-rings to seal properly in the bore. He's running a 20" B&C and I'm going to run it to verify it's still oiling enough.
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 07, 2016, 06:35:46 PM
XP, if your just playing lean your XT down on the high speed jet , these saws run pretty good in a wide range on jet setting but run very good only in a small area on jet setting . My xts hit the coil limiter real fast . The air filter makes a big difference as well
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 07, 2016, 07:50:31 PM
Quote from: ehp on April 07, 2016, 06:35:46 PM
XP, if your just playing lean your XT down on the high speed jet , these saws run pretty good in a wide range on jet setting but run very good only in a small area on jet setting . My xts hit the coil limiter real fast . The air filter makes a big difference as well

When the weather breaks I am going to tune my saw properly.  There is definitely more to be had out of it, it's running "pretty good" as you stated and  its enough to put a smIle on my face. Looking forward to getting it spinning to its potential.  A couple questions for ya.

1)  what type of air filter do you run?  I'm running the factory high top filter.

2)  do you widen the transfers toward the intake.  I widened mine toward the exhaust.

Thanks.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 07, 2016, 09:08:42 PM
I'm guessing he is talking about the white mesh filter like the one I put in the 575. It looks more free flowing than the standard HD filters we have.
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 07, 2016, 09:55:03 PM
my saws come from where they get a lot of snow so you will not get the high top filter saw , they only come in the low top and the filter is I think 80 micron mesh or whatever the least restricted filter Husky uses . I have seen lots of saws around here that run the flauk type filter and you really need to keep those as clean as possible . Even the mesh type can look real clean but still cut down on the amount of air that goes through it . As far as what I do on the transfers on these saws is I open both ends up so towards ext. port and towards intake port . Transfer ports are to small so you need to open them up to move air and that is why you need to open the ext. port up as well to help the transfer ports to move the air . The whole transfer port needs to be worked over right from the crankcase up
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 08, 2016, 06:07:05 AM
Quote from: ehp on April 07, 2016, 09:55:03 PM
my saws come from where they get a lot of snow so you will not get the high top filter saw , they only come in the low top and the filter is I think 80 micron mesh or whatever the least restricted filter Husky uses . I have seen lots of saws around here that run the flauk type filter and you really need to keep those as clean as possible . Even the mesh type can look real clean but still cut down on the amount of air that goes through it . As far as what I do on the transfers on these saws is I open both ends up so towards ext. port and towards intake port . Transfer ports are to small so you need to open them up to move air and that is why you need to open the ext. port up as well to help the transfer ports to move the air . The whole transfer port needs to be worked over right from the crankcase up

Thanks for the filter and transfer information. 
   I did open my transfers every where as you described.  The only portion I didn't touch is the taper toward the intake inside the bore.  I widened the intake side up to where that taper starts...if that makes sense.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 09, 2016, 03:27:41 PM
https://youtu.be/zOn_3ZD1Uek

Skip chain on the 24, full comp on the 20.  Tach showing between 12.5 and 12.7k in the cut.  I can say with complete certainty that my saw is done. GTG tomorrow!
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 09, 2016, 04:01:27 PM
Guys, we did a side-x-side comparison between Josh's 372 and his friend's Johnny-Red 2166. Now I'll grant that the 2166 is a factory de-tuned 372, but having said that, the stark difference between the pair cannot be understated!

You should post up that vid for the heck of it. ;)

My Dubya took to the final changes pretty good too. :D
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 09, 2016, 09:08:43 PM
Quote from: RIDE-RED 350r on April 09, 2016, 04:01:27 PM
Guys, we did a side-x-side comparison between Josh's 372 and his friend's Johnny-Red 2166. Now I'll grant that the 2166 is a factory de-tuned 372, but having said that, the stark difference between the pair cannot be understated!

You should post up that vid for the heck of it. ;)

My Dubya took to the final changes pretty good too. :D

This is sooooo not fair but here it is.
https://youtu.be/9hzT4DBqVqg
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 09, 2016, 09:44:01 PM
the xt is looking pretty good , with the wider ext port and more transfer port porting you will gain no more rpms in the cut , maybe a couple hundred but gain more torque at that rpm. Not many guys like the xt design but I like them and I make my money running them. I have zero problems bolting the 36 inch bar/chain setup on mine and cutting whatever needs to be cut with a ported xt and that's with full comp chain . I was quite surprised the first time I put the 36 inch bar on as the xt saw cut pretty flipping good , my 390 doesnot get much cutting time on it
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 09, 2016, 10:14:08 PM
Quote from: ehp on April 09, 2016, 09:44:01 PM
the xt is looking pretty good , with the wider ext port and more transfer port porting you will gain no more rpms in the cut , maybe a couple hundred but gain more torque at that rpm. Not many guys like the xt design but I like them and I make my money running them. I have zero problems bolting the 36 inch bar/chain setup on mine and cutting whatever needs to be cut with a ported xt and that's with full comp chain . I was quite surprised the first time I put the 36 inch bar on as the xt saw cut pretty flipping good , my 390 doesnot get much cutting time on it

Thanks for the feedback Ed, it is very much appreciated.  With how it's running now it's hard to imagine there's more to get out of it.  And please don't take that as I don't believe you because I absolutely do.   I am just that happy with it.  You're making me think that maybe it's not done...lol!
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 10, 2016, 08:53:00 AM
you did a good job and yes there is more still in the saw . I am sure there is lots of the saw porters that have not gotten as much out of their xts as you have so that is something to be proud of . Keep up the good work and have fun
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 10, 2016, 11:47:29 AM
I found my manifold I needed in the back seat of the Expedition yesterday. Wife got it out of the mail Wednesday.  ::) I installed it yesterday. The saw runs good but I still feel there is something wrong with the low side. The saw never stalls no matter how far the low is backed out.
I am looking for a camera man today.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 10, 2016, 09:27:04 PM
Thanks Ed, that's a pretty humbling compliment.  The fun is sure to continue with my 357XP!
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 10, 2016, 09:29:05 PM
Quote from: 49er on April 10, 2016, 11:47:29 AM
I found my manifold I needed in the back seat of the Expedition yesterday. Wife got it out of the mail Wednesday.  ::) I installed it yesterday. The saw runs good but I still feel there is something wrong with the low side. The saw never stalls no matter how far the low is backed out.
I am looking for a camera man today.

What are the chances that your unlimited coil advance is jacked up?  If I remember correctly you said there was something different about it that you didn't like when you first ran it.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on April 10, 2016, 10:15:23 PM
I was privileged to run both the saw of focus in this thread today...and I can tell you they are very strong saws! A successful set of builds for certain!
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 10, 2016, 10:17:48 PM
Thanks Walt. And thanks for hosting, we had a great time!
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 11, 2016, 06:27:44 AM
Quote from: weimedog on April 10, 2016, 10:15:23 PM
I was privileged to run both the saw of focus in this thread today...and I can tell you they are very strong saws! A successful set of builds for certain!

Thanks!  Had a great time and I think it would a crime to not repeat it at some point. 
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 11, 2016, 09:38:51 AM

What are the chances that your unlimited coil advance is jacked up?  If I remember correctly you said there was something different about it that you didn't like when you first ran it.
[/quote]
The idle has been the same with either coil.

I made three videos yesterday. I am now uploading them to youtube.
I used 28" oak and compared my 365 to a stock but muffler modded 2188, two cuts each with same bar and chain. The results were the exact same cut times, 30 seconds. Amazing!
In the third video I ran my modded, by EC Copsley, 390 with a 32"inch bar and semi chisel chain. The first cut was 24 seconds. I may have touched the gravel because the second cut was 26 seconds.
I am very pleased with the results. ;D I will use the saw this way for a while and then go back and make other changes.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 11, 2016, 11:22:30 AM
Quote from: 49er on April 11, 2016, 09:38:51 AM

What are the chances that your unlimited coil advance is jacked up?  If I remember correctly you said there was something different about it that you didn't like when you first ran it.
The idle has been the same with either coil.

I made three videos yesterday. I am now uploading them to youtube.
I used 28" oak and compared my 365 to a stock but muffler modded 2188, two cuts each with same bar and chain. The results were the exact same cut times, 30 seconds. Amazing!
In the third video I ran my modded, by EC Copsley, 390 with a 32"inch bar and semi chisel chain. The first cut was 24 seconds. I may have touched the gravel because the second cut was 26 seconds.
I am very pleased with the results. ;D I will use the saw this way for a while and then go back and make other changes.
[/quote]

Can't wait to see your saws in action!  That's an impressive achievement to have your XT neck and neck with a 2188.  Did you do any work to your XT beyond gutting, delete, and timing?

Glad to hear it's running right again:)

What's your youtube handle so I can find your videos?
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 11, 2016, 05:44:23 PM
First video 365xt
https://www.youtube.com/watch?v=MCz8HmkiPrU
Second video 2188 Muffler Mod
https://www.youtube.com/watch?v=PaUaF5-3Y6s
Third EC390 with semi-chisel chain
https://www.youtube.com/watch?v=9yIdYWKMwnw
I told my wife just film the saw and the log! :-\
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 11, 2016, 05:59:34 PM
Now THAT is a log to strength test a saw with! Nice work :)
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 12, 2016, 12:44:51 AM
you should of put the 32 inch on the other saws as well , that short bar hurts their cutting times cause your cutting with the tip of the bar and push on them, none of those cuts show how strong any of the saws were , if your looking at hearing a saw scream that's fine but if your looking to show power then use the power the saw has also guys if your cutting for times say at a GTG never rock your saw, the fastest way through a log is in a straight line . Rocking a saw adds cut time cause the saw will cut a wider kerf, you think not then get a caliper and measure the cut and you will find you cut .030 to .050 wider if you rock the saw . A good operator can make a so so saw look great and the same goes the other way ,
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 12, 2016, 12:46:38 AM
that size of wood is just a average smaller size tree I cut here
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 12, 2016, 01:27:40 AM
Now remember guys , the XT models do not take well to porting , lots of guys have said this . From what I have seen the xt out cut the stihl 661 in big wood like 30 plus inch hardwood like red oak. I know I did a test with my ported 562 against a stock 395 and a stock 372 in 27 inch  frozen red oak , all running the same bar and chain, the 395 won but not by much over the 562 , the 372 was a long ways behind 
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 12, 2016, 05:42:24 AM
Quote from: ehp on April 12, 2016, 01:27:40 AM
Now remember guys , the XT models do not take well to porting , lots of guys have said this . From what I have seen the xt out cut the stihl 661 in big wood like 30 plus inch hardwood like red oak. I know I did a test with my ported 562 against a stock 395 and a stock 372 in 27 inch  frozen red oak , all running the same bar and chain, the 395 won but not by much over the 562 , the 372 was a long ways behind

   It's amazing what folks have said about XT's just because it's not the same as the previous model.   I think mine took to porting just fine:)  Were it not for knowledge I've gained here, I may have accepted those baseless opinions and never tried to port my saw.
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 12, 2016, 08:51:28 AM
Quote from: ehp on April 12, 2016, 01:27:40 AM
Now remember guys , the XT models do not take well to porting , lots of guys have said this . From what I have seen the xt out cut the stihl 661 in big wood like 30 plus inch hardwood like red oak. I know I did a test with my ported 562 against a stock 395 and a stock 372 in 27 inch  frozen red oak , all running the same bar and chain, the 395 won but not by much over the 562 , the 372 was a long ways behind

Yes, xt's don't take well to porting :D . 365xt is two pounds lighter and cuts the same as a  muffler mod 2188 makes me happy. Now that it has stopped raining, I want to do one more comparison with the 390 and chisel chain.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 12, 2016, 09:12:35 AM
Quote from: 49er on April 12, 2016, 08:51:28 AM
Quote from: ehp on April 12, 2016, 01:27:40 AM
Now remember guys , the XT models do not take well to porting , lots of guys have said this . From what I have seen the xt out cut the stihl 661 in big wood like 30 plus inch hardwood like red oak. I know I did a test with my ported 562 against a stock 395 and a stock 372 in 27 inch  frozen red oak , all running the same bar and chain, the 395 won but not by much over the 562 , the 372 was a long ways behind

Yes, xt's don't take well to porting :D . 365xt is two pounds lighter and cuts the same as a  muffler mod 2188 makes me happy. Now that it has stopped raining, I want to do one more comparison with the 390 and chisel chain.

Your saw looks real strong, nice work Niner.  Did you end up doing a full port job on it?
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 12, 2016, 09:26:37 AM

[/quote]

Yes, xt's don't take well to porting :D . 365xt is two pounds lighter and cuts the same as a  muffler mod 2188 makes me happy. Now that it has stopped raining, I want to do one more comparison with the 390 and chisel chain.
[/quote]

Your saw looks real strong, nice work Niner.  Did you end up doing a full port job on it?
[/quote]
Yes, but very conservative.
Title: Re: 372XP X-Torq Modding
Post by: rburg on April 12, 2016, 12:55:42 PM
Glad to see your 365xt running so well. Next time we gtg I will let you run mine that Wiggs did for me.
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 12, 2016, 05:45:26 PM
49er the length of bar plays a big part in cut times as well , get a full chisel chain than run it on all the saws and then you can see what each saw has . Lift your test log up abit so you donot hit the ground and you can cut right out the bottom of the log
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 12, 2016, 07:32:59 PM
Up until 3 days ago I always ran a skip chain on my 372 simply because it was less teeth to sharpen.  The full comp chain is faster hands down when compared to the skip.  It also feels better to me because the saw draws itself through the wood more.  The skip takes more effort on my part to push through the wood.
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 12, 2016, 08:15:13 PM
Quote from: ehp on April 12, 2016, 05:45:26 PM
49er the length of bar plays a big part in cut times as well , get a full chisel chain than run it on all the saws and then you can see what each saw has . Lift your test log up abit so you donot hit the ground and you can cut right out the bottom of the log
I got a video today with full chisel and I was thinking I need to raise that log up.
I am not used to a 32 inch bar every time I get it out I hit something. :D
https://youtu.be/WnvEAb_h7Uw
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 13, 2016, 05:47:48 AM
Those cuts sound better.  The wasn't screaming as much.  How did you like the full comp chain compared to the skip?
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 13, 2016, 09:34:13 AM
Quote from: XP_Slinger on April 13, 2016, 05:47:48 AM
Those cuts sound better.  The wasn't screaming as much.  How did you like the full comp chain compared to the skip?

The first cut with the 390 was with semi chisel.  I have tried skip and don't like it in hardwood, it may be ok in softwood but I don't cut much softwood.  Skip chain is not very smooth to me.
Title: Re: 372XP X-Torq Modding
Post by: HolmenTree on April 13, 2016, 12:17:47 PM
Good way to cut.... holding the saw level. smiley_thumbsup
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 13, 2016, 04:30:54 PM
That's a good running saw 49er. :)

Can't wait to see Weimedogs vids!
Title: Re: 372XP X-Torq Modding
Post by: weimedog on April 14, 2016, 11:38:47 PM
Uploading now. I rushed a bit. Just got back from down state, didn't really have time to build a finished video so  I am uploading what I have to this point......:)

Interesting your fastest times were when rocking/using the bucking spikes... actually a trend with you two across three saws. I cut the video back to highlights but can add more should you doubt that :) Think when the chain stopped you just cleaved the wood with the bar...

Points the fact there is more tweaking that can be done in the chain department.....:)
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 15, 2016, 08:40:13 AM
Torque!! ;)
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 15, 2016, 01:22:44 PM
I'm not seeing the vid....  ???
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 15, 2016, 02:00:02 PM
Quote from: RIDE-RED 350r on April 15, 2016, 01:22:44 PM
I'm not seeing the vid....  ???

Is there a video to be seen? :-\
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 15, 2016, 02:13:32 PM
It's on Youtube Joe...I emailed you the link.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 15, 2016, 05:14:53 PM
Yep I got. Very cool vid Walt!

49er: I think Walt wants to do some editing to the vid before he posts it here. I will let him list it up here when he's ready.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 15, 2016, 05:21:46 PM
Oh and on rocking the saw on the dogs: we do understand that letting the saw eat evenly is a good test of the saw in general for RPM in the cut and whatnot. But, most people (including us) will rock the saw on the dogs in a normal work situation. We also feel that this is a good test of how much torque the saw has and how well it will maintain under a heavy load. I like to see how much the saw can be force-fed before it cries Uncle. If you can put a saw on the dogs and roll 'er down into hard maple with some authority and she keeps on chugging, I think that makes for a pretty strong saw. :)
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 15, 2016, 06:40:39 PM
yes but in most cases if you have to use the dogs to draw your saw down then your saw is not cutting , either because , dull, rackers not low enough or not geared high enough . You should not have to push hard on your saw to make it cut , if you are then your loosing cutting speed and your working hard than you need to
Title: Re: 372XP X-Torq Modding
Post by: weimedog on April 16, 2016, 01:20:53 AM
All true. How many time should you plan to sharpen or replace a chain on the job to keep things optimal?
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 16, 2016, 06:20:14 AM
Quote from: weimedog on April 16, 2016, 01:20:53 AM
All true. How many time should you plan to sharpen or replace a chain on the job to keep things optimal?

More times than most guys (including myself) would want to that's for sure.  I'm sure we've all pushed a chain a few cuts or logs too far.  Can't slow down production to sharpen a chain!  Lol!  But in reality, the dull chain probably has the same cumulative effect on lost time in the long run. Not to mention the extra work the operator is doing to make it cut.  Watched a an inexperienced person take 5 minutes to get through a 16" piece of ash once.  Once he completed the cut i suggested he sharpen the chain but he insisted it was just because the log was frozen.  I tried to help him out, even offered to sharpen it for him because I don't think he knew how but he refused.  So I went back to splitting...some people I guess.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on April 16, 2016, 08:21:57 AM
Yup, Finding that right "blend" of sprocket, bar, chain, sharpening technic etc. can yield nice gains in the cut times. That was demonstrably obvious. Finding that blend for your particular saw and work environment sometimes can be a challenge as that analysis varies from person to person, job to job, log to log,and with the equipment you have along with associated costs.. AND everyone has an opinion! (but its your time and money) So you build a compromise based on the situation. At events like ours, the interest usually is in the saw so the chain side isn't even thought about by most as its about the saw damit! Right until the cookie bakery gets fired up. That file can be way more important than the screw driver (spline tool?) ( I have a very good friend who has for the longest time come with a truck full of saws with chains in various states of disrepair...:) I preyed on that for years, all in fun of course....but a confession just the same )

(You have more speed in that saw on THAT particular log.....with sprocket size, raker depth, bar selection etc. :) )
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 16, 2016, 07:22:50 PM
Picked up a standard TSB 24" for the XPW yesterday Walt. Josh and I cut a mess of wood at our dads place today. I wasn't able to get the light bar as GKS was out of stock on those. But  I don't have a single bad word to say about the standard. Price was $55 and I thought that to be a very good deal. Pretty sure they get darn near the same for an Oregon Power Match. :)
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 16, 2016, 07:42:40 PM
New TSB :)
(https://forestryforum.com/gallery/albums/userpics/41717/IMG_20160416_093603923.jpg)
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 16, 2016, 08:36:12 PM
What gauge did you get?
Ya got enough saws in the truck you don't need to take any gas. LOL
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 16, 2016, 10:02:57 PM
I got .050 gauge, I'm told that's the only size they make as of yet.

As for the truckload of saws, well of course I wanted to run my 372 today. The other saws are a 394 that belongs to my employer that I overhauled last week. I brought it today to work it in wood some and make sure everything is good to go. Next is my little 136 I brought to let my 12 year old do a little cutting with today. I plan to give it to him for his birthday coming later this month. Last is my 346NE. I just felt like running that saw today too. It's bone stock still, not even a muffler mod...and it still puts a smile on my face when I run it. :)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 17, 2016, 07:38:23 PM
I'd say we had an (Admin Edit) day at mom and dads yesterday.  Bar looks good Joe! :)
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 18, 2016, 07:19:31 AM
Finally got some work time vs play time on my 2166 yesterday. Have to conclude that without the divider in the carb it's become a bit of a gas pig. I liked it better with the rest of the intake gutted, but with the divider still in the carb, so I'm going to return it to that mode.
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 18, 2016, 09:21:06 AM
Quote from: Spike60 on April 18, 2016, 07:19:31 AM
Finally got some work time vs play time on my 2166 yesterday. Have to conclude that without the divider in the carb it's become a bit of a gas pig. I liked it better with the rest of the intake gutted, but with the divider still in the carb, so I'm going to return it to that mode.
I assume that the saw uses less gas with the divider in the carburetor but the rubber manifold removed?
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 18, 2016, 11:11:31 AM
Yes, and next step is to put the divider back in and like yesterday run it in a work environment and see how she does. Up until yesterday, I 've only done a few cookie cuts to get a feel as to how it runs. Cookies can show you that much, but you can't really draw any conclusions until you put it to work. I also think the carb adjustments were more stable with the divider in there. Another thing I'll evaluate when I get it back together.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 18, 2016, 07:38:07 PM
Quote from: Spike60 on April 18, 2016, 11:11:31 AM
Yes, and next step is to put the divider back in and like yesterday run it in a work environment and see how she does. Up until yesterday, I 've only done a few cookie cuts to get a feel as to how it runs. Cookies can show you that much, but you can't really draw any conclusions until you put it to work. I also think the carb adjustments were more stable with the divider in there. Another thing I'll evaluate when I get it back together.

Other than fuel economy, I wonder if the intake pulse is can truly take advantage of the large venturi of the carb.  I worked my saw for a day this past Saturday on a log pile and I got roughly 3 face cord cut on 2 tanks of fuel.  Not sure how that compares to your saw Spike.  Next time I'm working it I'll record how long it takes to run a tank through it.  As you observed, it definitely drinks faster than it used to but I never recorded how the fuel mileage was when it was stock so I'm at a loss for a scientific comparison.  That being said, I'm going to leave mine as is for now because it's running great.  Once I'm done working it and I can play with saws again I may do some experimenting as you are. 
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 19, 2016, 06:45:31 AM
Only thing I recorded, which can't be repeated here, was my reaction when the saw ran out of fuel.  :) Seemed very pre-mature to me. I hadn't touched it since running it a little bit up at Walt's the previous weekend. Definitely expected more cutting time than I got. I've got lots of 372 based saws, and I have a feel for what to expect fuel wise with them.

I'll be looking more closely at the fuel issue after I put the divider back in. I think my buddy Todd is starting a 5 acre clear cut job this weekend, so I'll run it there on Saturday and report back here with the results. Reminds me I've got 2 of his saws in the shop to get ready also.  :o 

Of course this brings up the question of acceptable trade off between power gained and fuel usage. Often the "skeleton in the closet" with modded saws. As it is now, what I've done is just too thirsty to be considered a practical work saw build. I need to dial it back a bit.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 19, 2016, 04:47:07 PM
I owe you an apology for my part in the lack of cutting time at our GTG Spike.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 19, 2016, 05:45:07 PM
Quote from: Spike60 on April 19, 2016, 06:45:31 AM
Only thing I recorded, which can't be repeated here, was my reaction when the saw ran out of fuel.  :) Seemed very pre-mature to me. I hadn't touched it since running it a little bit up at Walt's the previous weekend. Definitely expected more cutting time than I got. I've got lots of 372 based saws, and I have a feel for what to expect fuel wise with them.

I'll be looking more closely at the fuel issue after I put the divider back in. I think my buddy Todd is starting a 5 acre clear cut job this weekend, so I'll run it there on Saturday and report back here with the results. Reminds me I've got 2 of his saws in the shop to get ready also.  :o 

Of course this brings up the question of acceptable trade off between power gained and fuel usage. Often the "skeleton in the closet" with modded saws. As it is now, what I've done is just too thirsty to be considered a practical work saw build. I need to dial it back a bit.

That's the million dollar question:  Is the power gained worth the extra fuel?

For my situation I can happily say absolutely!  But I'm not dealing with the volume of saws that you are from your perspective.
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 20, 2016, 05:39:50 AM
Quote from: RIDE-RED 350r on April 19, 2016, 04:47:07 PM
I owe you an apology for my part in the lack of cutting time at our GTG Spike.

No, not at all. The hedgerow work we were doing really didn't require 70cc saws. I was running a 49SP up there. We never really got a chance to do the 70cc comparisons in the upper field. After we had had dinner and BS it was getting kind of late to go back up the hill.
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 20, 2016, 05:50:16 AM
Quote from: XP_Slinger on April 19, 2016, 05:45:07 PM


That's the million dollar question:  Is the power gained worth the extra fuel?

For my situation I can happily say absolutely!  But I'm not dealing with the volume of saws that you are from your perspective.

I looked at mine in the context that I had already been doing a step by step mod, with some nice gains. It's just that the last step of removing the carb divider was one step too many. The best the saw ran seemed to be with the intake gutted and carb divider in place.
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 20, 2016, 04:02:20 PM
Quote from: Spike60 on April 20, 2016, 05:39:50 AM
Quote from: RIDE-RED 350r on April 19, 2016, 04:47:07 PM
I owe you an apology for my part in the lack of cutting time at our GTG Spike.

No, not at all. The hedgerow work we were doing really didn't require 70cc saws. I was running a 49SP up there. We never really got a chance to do the 70cc comparisons in the upper field. After we had had dinner and BS it was getting kind of late to go back up the hill.

I appreciate that, but next time I'll try and make sure the BS session doesn't cut into cutting time too much. ;) However, it was darned good discussion. :)

On the carb divider: Am I correct in thinking that putting the carb divider back in would then bring it back to feeding clean air only to the strato ports?
Title: Re: 372XP X-Torq Modding
Post by: weimedog on April 20, 2016, 05:47:41 PM
On the out side looking in on this discussion....but if the boot has the guts cut out, then the air / gas air will mix in that space right? There would be a differential in the mix from top to bottom so the "leaner" part would favor the strato ports I would think. My question would be around the carb settings as  the raw air above the divider will need some fuel too. Wish I had the time to mess with these and see for myself. Not until much later in the year at the rate I'm going now..:(
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 20, 2016, 07:47:59 PM
Walt brings a question to my mind with his above post....

Josh: I believe you cut the divider out of the boot. Am I right??

Spike: Is the divider removed from your boot as well??

This is curious to me now... And I think I might understand why the fuel mileage takes a dump when you pulled the carb divider... Bear with me here just a bit..

I was heavily into snowmobiles a few years back, soaking up every bit of tech and info I could get my eyes on.. I read an article by Olav Aaen (considered one of the founding fathers of high performance 2-stroke tuning in the area of snowmobile racing) about carb sizes and why bigger isn't always better. Every engine has a carb size range that will be best suited to it based on engine displacement, along with bore and stroke configuration. He stated that in the old days of sled flat track racing guys would put huge 44mm twin carbs on their twin cyl 440's and because the carbs were so large for the engine size and design of the day, they had to be jetted extremely rich..more rich than one would ever expect. Power was peaky, lightswitch like, all or nothing, very rich down low to get descent results up top. And the reason for the abnormally fat jetting was that the engine displacement could not pull the volume of those large carb venturis fast enough for good fuel delivery and atmomization. Basically, the carbs were too large for engines of that size to generate good intake velocity. Lower intake velocity through the carb venturi means less efficient fuel pickup, atomization, and delivery. So to make the engine run descent one would have to go much larger with jetting making up for the lack of velocity with alot more fuel...

So, I said all that to say this... Is it possible that with the dividers removed that to a lesser degree than the above story, you are losing enough intake velocity to be required to run fatter jetting to make up the difference, thus causing fuel consumption to skyrocket?
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 20, 2016, 08:57:26 PM
That's exactly what I was thinking Joe, just hadn't figured out how I was going to illustrate the thought. 
    With the divider in place, the volume of air moving through the carb would be nearly identical to with it removed.  The cross sectional area of the divider wouldn't create any significant obstruction in the venturi IMO.  What the divider will do is optimize the pressure signal that is pulling fuel out of the main jet.  These theories coincide with Spikes observation that jet adjustments were more stable with the divider in place.  I think I'll check the tune on my saw then put the divider back in and see where I have to go.

   On your earlier question Joe, putting the divider back in won't take our saws back to strato mode at this point.  The strato division is in 3 separate parts: Filter mount, carb and intake.  All of which have been removed. 
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 20, 2016, 11:15:00 PM
I ran my saw with the carb divider in place and the filter adapter and intake boot gutted. I could tell no difference in performance but I was not looking a fuel efficiency.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 22, 2016, 06:34:34 PM
Quote from: Spike60 on April 20, 2016, 05:50:16 AM
Quote from: XP_Slinger on April 19, 2016, 05:45:07 PM


That's the million dollar question:  Is the power gained worth the extra fuel?

For my situation I can happily say absolutely!  But I'm not dealing with the volume of saws that you are from your perspective.

I looked at mine in the context that I had already been doing a step by step mod, with some nice gains. It's just that the last step of removing the carb divider was one step too many. The best the saw ran seemed to be with the intake gutted and carb divider in place.

Ran my saw again today.  1 tank lasted 34 minutes on the log pile.  I wasn't expecting it when it ran out but that might be because I'm in better shape than I have been in a while so i wasnt as tired as I normally am after a tank...lol.  I'm still stuck at not knowing any better with fuel economy.  I'm looking forward to reading your results Spike.  Now that my saw is filthy and the chain is dull I'll put my divider back in when I have it partially dismantled for cleaning this weekend.
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 26, 2016, 05:12:56 PM
Ran the saw some on Sunday at the GTG. Still think the fuel use is a bit on the thirsty side. The adjustments did settle down though.

Bear in mind that I gutted my saw after doing a few other mods like cutting the piston skirt and deleting the base gasket. It may simply be a case of mixing 2 recipes that don't really fit together. I'm thinking of either going back to the non-gutted intake and leaving it that way, or maybe try it with an uncut piston. It was running pretty good, but we're always looking for a little more, so we try a little more. I suspect that the waste has something to do with the fact that the "undivided" intake now feeds fuel into the strato ports which gets blown out the muffler rather than getting burned.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 27, 2016, 05:33:20 AM
Quote from: Spike60 on April 26, 2016, 05:12:56 PM
Ran the saw some on Sunday at the GTG. Still think the fuel use is a bit on the thirsty side. The adjustments did settle down though.

Bear in mind that I gutted my saw after doing a few other mods like cutting the piston skirt and deleting the base gasket. It may simply be a case of mixing 2 recipes that don't really fit together. I'm thinking of either going back to the non-gutted intake and leaving it that way, or maybe try it with an uncut piston. It was running pretty good, but we're always looking for a little more, so we try a little more. I suspect that the waste has something to do with the fact that the "undivided" intake now feeds fuel into the strato ports which gets blown out the muffler rather than getting burned.

Do you think you're loosing that much out the muffler?  The strato pulse is relatively small compared to the main intake and I can't help but wonder if the reduced fuel economy is just a side effect of the saw simply making more power and needing the extra fuel.  Do you think that our gutted XT saws are using fuel faster than a ported 372 OE?
Title: Re: 372XP X-Torq Modding
Post by: weimedog on April 27, 2016, 06:26:46 AM
Again on the out side looking in on this one....but just a few comments

Math. All things being equal relative to the efficiency of the overall package, the fuel usage should go up proportionally with the power gains.....but doing things by eye and hand its virtually impossible for "all things being equal" to happen. Also changing how the systems work complete changes the system so things aren't equal.

My instincts would point to more fuel used in similar situations. But yet again how can that be replicated from place to place and job to job?

Bottom line. Expect more fuel usage. Then be really pleased if it doesn't change enough for you to notice....:) I wouldn't over analyze the saw because its major accomplishment is the smile factor. Just enjoy the thing!
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 27, 2016, 09:41:38 AM
Yeah, that's what I'm going to do. This discussion is getting a little on the "microscopic" side for me, and you know how my mind works with that stuff.  :D 

I'm going to put it back to the way I had it. Was running pretty nice and doing all that I asked of it.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 27, 2016, 05:11:52 PM
Quote from: weimedog on April 27, 2016, 06:26:46 AM
Again on the out side looking in on this one....but just a few comments

Math. All things being equal relative to the efficiency of the overall package, the fuel usage should go up proportionally with the power gains.....but doing things by eye and hand its virtually impossible for "all things being equal" to happen. Also changing how the systems work complete changes the system so things aren't equal.

My instincts would point to more fuel used in similar situations. But yet again how can that be replicated from place to place and job to job?

Bottom line. Expect more fuel usage. Then be really pleased if it doesn't change enough for you to notice....:) I wouldn't over analyze the saw because its major accomplishment is the smile factor. Just enjoy the thing!

Good points.  And I am enjoying the heck out of my DIY ported saw  :)
Title: Re: 372XP X-Torq Modding
Post by: ehp on April 28, 2016, 04:50:02 PM
Ok you guys do what you want , this is just how I setup and run my saws, I cut a big fence row yesterday about 200 pine trees ,I only fell them as the other guys were topping them , about 3/4 of a mile long .A lot of the trees were in the 20 inch on the stump range , some smaller but some as big as 36 inch on the stump . I ran my ported 372, a stock 372 and a stock 562 . The stock 562 lasted about 30 minutes per tank, the stock 372 lasted about 38 or so minutes per tank . the ported 372 lasted about 25 minutes per tank . I ran the ported 372 pretty much the whole time, just put a tank threw each of the others . Yep my ported 372 uses more fuel per minute than either of the other stock saws BUT that saw cuts close to twice as many trees per minute as the stock 372 does . On say a test cut of 100 cuts I'm sure a stock 372 will be abit better on fuel but not a big difference but will take a lot longer time to make those 100 cuts compared to the ported 372 . I doubt very much if I burn $2 to $4 a day more fuel than what I would with the stock saw but I do the same amount of work in a lot lease time . I guessing 2 to 3 more hours a day to do the same amount of work , If big timber that number will grow to closer to 4 hours a day . My time is worth money so I gladly spend abit more on fuel if that means I get a couple more hours to produce timber . On a normal 7 day week I may spend $25 more on fuel but gain 14 to 20 hours more production . Its pretty easy to see why I run ported saws . Yes they burn more fuel per hour but they also cut a lot more wood per hour . As far as how the ported saw runs compared to the stock saw on the jetting part , no contest the ported saw is far better on every part of running compared to stock . But this is just me and what I do , you guys do whatever you feel like doing
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 28, 2016, 07:38:01 PM
Quote from: ehp on April 28, 2016, 04:50:02 PM
Ok you guys do what you want , this is just how I setup and run my saws, I cut a big fence row yesterday about 200 pine trees ,I only fell them as the other guys were topping them , about 3/4 of a mile long .A lot of the trees were in the 20 inch on the stump range , some smaller but some as big as 36 inch on the stump . I ran my ported 372, a stock 372 and a stock 562 . The stock 562 lasted about 30 minutes per tank, the stock 372 lasted about 38 or so minutes per tank . the ported 372 lasted about 25 minutes per tank . I ran the ported 372 pretty much the whole time, just put a tank threw each of the others . Yep my ported 372 uses more fuel per minute than either of the other stock saws BUT that saw cuts close to twice as many trees per minute as the stock 372 does . On say a test cut of 100 cuts I'm sure a stock 372 will be abit better on fuel but not a big difference but will take a lot longer time to make those 100 cuts compared to the ported 372 . I doubt very much if I burn $2 to $4 a day more fuel than what I would with the stock saw but I do the same amount of work in a lot lease time . I guessing 2 to 3 more hours a day to do the same amount of work , If big timber that number will grow to closer to 4 hours a day . My time is worth money so I gladly spend abit more on fuel if that means I get a couple more hours to produce timber . On a normal 7 day week I may spend $25 more on fuel but gain 14 to 20 hours more production . Its pretty easy to see why I run ported saws . Yes they burn more fuel per hour but they also cut a lot more wood per hour . As far as how the ported saw runs compared to the stock saw on the jetting part , no contest the ported saw is far better on every part of running compared to stock . But this is just me and what I do , you guys do whatever you feel like doing

I couldn't be happier with how my saw runs after following your guidance.  I found the fuel mileage discussion interesting simply because it was geared toward potentially finding out new information.  In the end I credit the fact that the saw is making A LOT  more power than it was before. Extra power needs extra fuel, no big deal to me. 
Title: Re: 372XP X-Torq Modding
Post by: 49er on April 28, 2016, 09:15:21 PM
EHP, I would say you have the fuel consumption vs. productivity thing figured out. The rest of us do not make a living with a saw but if we did I am sure we would come to the same conclusions. And besides fast saws are more fun.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 29, 2016, 05:09:04 AM
Quote from: 49er on April 28, 2016, 09:15:21 PM
EHP, I would say you have the fuel consumption vs. productivity thing figured out. The rest of us do not make a living with a saw but if we did I am sure we would come to the same conclusions. And besides fast saws are more fun.

Yes they are! 
Title: Re: 372XP X-Torq Modding
Post by: Spike60 on April 29, 2016, 03:07:26 PM
OK, hold on a minute here. I was afraid that my comments might get misconstrued, and I meant no disrespect to Ed's, or anyone else's recipe on these X-torq saws. I have a LOT of respect for your knowledge Ed, even though you sometimes show signs of being just as crotchety as I am.  :) This has been a really good thread, and one of the more informative I've seen in a long while. Your metric of putting down twice as many trees for a small price in fuel use makes complete sense. But I think I turned my saw into much more of a lush, and I'm betting the fuel use was much poorer than yours.

To try to clarify, I think that adding the complete gutting process to what I had already done to my saw was what likely caused the fuel consumption to be what I considered kind of excessive. Following Ed's advice from the beginning would no doubt have resulted in a much better performing saw. But I was halfway down one road, and then went down a different one. So, I'm thinking the combo was the deal with my saw. Just sharing what happened to me so no one stumbles down the same path and gets disappointed.

Are we all still happy?   :laugh:
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on April 29, 2016, 03:50:34 PM
Well I can't speak for Ed, but I certainly didn't take what you said in a negative way. I understand your approach and the reasons for it. Frankly, I think your approach gets overlooked sometimes on these saw forums because so many who want to step into the modded saw world are instantly drawn to hot-rod ported saws. To be clear here, I don't think ported saws are a bad thing at all, I now own one myself and LOVE it. I'm just trying to say that this whole thread, from your path Bob to Josh's full-on port job guided by Ed, has been incredibly informative and even though I don't own an XT myself I really enjoyed how everything developed. I was right there with Josh through most of the steps he took modding his XT and being that we did things in steps it was cool to see how the saw responded to each step. I did things in the same way with my XPW in terms of going in steps.

I think that this thread is hands down THE best XT modding thread I have seen on all three of the saw forums I participate in. There is literally something for everyone here, no matter what level of mods they want to pursue. And that is a VERY good thing!

Carry on Bob, your contributions to the community are appreciated, and the same is true pertaining to Ed :)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on April 29, 2016, 08:32:48 PM
I was never unhappy...just talkin bout stuff.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on May 01, 2016, 04:00:54 PM
So because of a long winded thread over on arborist site, I went through some archives and dug up some test cuts on that same log we hacked at when you were at the farm. So I put the 562 cuts that we did that same day and then backed it up with a couple from my Huztl 52mm build that date stamps say were a week later...same basic time frame. Thought you might get a laugh. (You really can't tell anything from this although I know some will try....figured I would post it here as you were quite familiar with the situation, that log,  and environment....:)  )

https://www.youtube.com/watch?v=4XRvLmOHW70
Title: Re: 372XP X-Torq Modding
Post by: RIDE-RED 350r on May 01, 2016, 06:31:46 PM
That Huztl 372 sure takes well to dogging in doesn't it. :)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on May 01, 2016, 07:47:06 PM
That's its point. A cheap and forgiving saw to run when you "eff up".  But you can see the power "order of magnitude" with times .. and it doesn't really bog...comes right back when its lugged like that.  Cheap saw to replicate for the "average" guy without a lot of special tools & experience. Its proven to be solid build. I suppose I could lean it out & put a black ignition on it, get some more transfer x-sectional area and make it scream and pick up some time. But that misses the point of that particular build. Pulls a 28 really well too when asked.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on May 01, 2016, 07:53:05 PM
Quote from: weimedog on May 01, 2016, 07:47:06 PM
That's its point. Torque.. But you can see the power "order of magnitude" with times .. and it doesn't really bog...comes right back when its lugged like that.  Cheap saw to replicate for the "average" guy without a lot of special tools & experience. Its proven to be solid build. I suppose I could lean it out & put a black ignition on it and make it scream and pick up some time. But that misses the point of that particular build. Pulls a 28 really well too when asked.

Purpose built and obviously performing great.  Nice saw bud
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 03, 2016, 09:52:57 PM
This thread is great! It's been a while, so I figure I'll ask on here... Are you all still happy with your mods, and in particular, gutting the strato splitter in the intake?

I'm most of the way through doing mine, but I'm hung up on gutting the strato. I talked to Spike on another forum, and he said he got the fuel usage deal figured out (he was just way rich, as it takes more turning on the screw for the same amount of change with the mods), but how are the rest of you liking it? More specifically, does it make a noticeable amount more power, or is it just easier to tune?

FWIW, squish on mine without the base gasket ended up being like .010, so I threw the piston in the mill and made enough of a pop-up to get .023-.025 squish by the 4-pieces-of-solder method. Doing the 1-solder through the plug hole method, I was getting .014, but I made a .015 pop-up, and ended up with .023-.025, so I'm guessing actual was around .010, if I had done the 4-solder method.

Other than that, I'm doing pretty much what you guys did. Took out the restrictors on my 2166, funneled the transfers out to the gasket size, took .020 off the cylinder skirt at the transfers, took .030 off of the intake side of the piston skirt, cleaned up, maybe took .015 off of the transfers all the way up and around the corner, took the exhaust outlet out to the gasket size and matched it to the muffler inlet, and will do a 288 muffler mod like I did on my 371xp.

(https://lh3.googleusercontent.com/x6Izg7nRmGpI-J_9RrxdZz2Tny3OJfL7XcnGJceNJUlD58Yfwi1SfUk1izqUyTXTmmBy1CDyu6a_BgV1ZYsW4ULgC2dGmIK9pVC38E4UoKltCUSXlzWKcJ5qNz9MiioPWvo0WgAniM0vexN8xKBT5fiFjX5lxagH2lYAqQVsxFpSgru4tN3vMhQqNG75t2EfpJsbFZ5FrWBzp8rVSxaTRXtarX0Q95ozrxF7RQFr8JdTlX1uK8aaDYP8_X_la-4FXkb_BmEtNI2LBPqVEElXxWsg6xV9StMGeOiXqHcTJuHdo1AFZqHbvSVVuYQjd6vNgTIYL8lgtQ6cfM4rfG9PH4JvYuvnw0GSVri5G0hQfOfcrecL5QRMHuku3J_msum7-C_sTfdxoJIXsBxzMbfBMnMHfW9_R_XcQzBwb-KGYfh8bf2_D9apmBlsySaujZBqcFHYdWzQvnFczSZB-ipOssA4UeOPAb2huGVEKgNnpZ2weI85eo4UsZSJfP4XowdNEtnXsjgji3qHCzb6usaLL78bBwP_NTchBFjNqsgV8pXJ_SZSZWsPvBKnLKb5kVg5xl9upF9-wU5-OvS2RQXJnF7U37yi-IeKouBqWmVuKQTibVEOKA=w359-h638-no)

(https://lh3.googleusercontent.com/iwKp6t0rwtbq1RIlCTNj8vYh4Wozv0kVmdEykZfdUqM8eSdOmhsbuXghzkNZmROz2qZqHYB9mmAgDbXrc717eypdMAZ6oLuinTFp0A6hV1rNxPdnEWthKAxO_qDQzJg7FdbVj0FRFgVNgQZAD1OJD69ZEwlarzZKn3_0d_taHLCHyoQCYeTbHYHgoWKIhzsgcUD1J8ng7WQdM34IVNr6jZ32_cPkhqGcPKLLkrAJ-tuujXoxVTG-6uH5pVdtOgG7rCCSFnZBp2txilOMK7r8-98KSNr31uSp2iqX1MfdQDFy_aXraewQlIyjdlxKNvsA_xS0_gA-_flSqm3XZLmEN6PXbUzn2PqBDVRkGejm142VBFBS1pVClAzd-pGGK4_MBaDtyVE3H0YesxuNN6kHmUlj65wTxz4HkRmMkOd76bp2O0h0nh9Ln0EiONN5PysYR6q778DZPbciTaXWR3OAZHpOD9IQ9G9sPA9eKL-9tnzsVi6BxYy01c6HFjU1QLLQI9RXeyD-JA6jGUJgxPh08AHCSj7N06O_J1oaMDPWbvwDvSYjY_jDRl0-nxkBVkSc0yzA6Sj-7ZwJXb8o-ZNiE1hd_CHPicCuIkOT3oPZJ9xCNVfzkw=w359-h638-no)

(https://lh3.googleusercontent.com/2jCwuTz7awkfk9lHDipPiYsVQ9YxkHDdmc6fwBlxXRGmV8VbZn6GDg46JZpQuKv7KCbFBiE2jWchLEXJzREc_-ymEFZr3oMbIudxdHngt0GskDHsim5OQClnNoGsfV8ueDcysWKvyWn_9GcY_fSjc_1J1tSJIlWs14hGbOro7R08mZjDx_BGoKmnQMw4iRjc_AfEtfX5lhDhyHXgPjmu9z9-WgOEMZsphg1r3jL1dqGP-wYKhBF9W8Oe76nsUAl4XtYBUznfjs8akpm7Ds7OFEGAy3TZQyr-U21l7p4Flp1fa3_GGSGGUHGAXIaBzZA33PBtoMYf5zLOrdAZyyNzZMWPs90ulXvsBjCHg4iYr9pQ3iMd1z6xk_Pb5r8LBN7lrN3fXP4mkqU9P5coQdBjkvIPFSc5v-AIBfrm6TGEJSe5m4mAwPbOPjbAvvVp7fRrv8qR87fpN6sfSGJTEvFowK6xqyc6o8g6hfUH8GDlG1kLH2aT4WIk6nWMZlKn7A0Pj4JjIIBw521XbnUTlOmYjflqAFE89ntS1W8w8_9aQ5aq8i8QLqeXt9eUS2WpuTGUdOzchHg5aPWD4Z23iIv9YDOfE9PWXpSMbl3i-SBG8YPvgw_uig=w359-h638-no)

(https://lh3.googleusercontent.com/gU8cWBk7wdaBFjM4V88s7EYkp4YHrUxP9UDPOrOXMjBKAfDfeUym-2HuYxuyNJab9odiCKYsbbX18wWkM3_aK-MR5SiiZQVm5GGQdTNv6NV8UsVj_CcNEGqgSEBXhr1rZfdw9iDSlxAfEnA8rzzLni27PfOwfgzLbemHiserNRob5PniTD56_j9DxKOSBq7lzOPPBE0V0G73KmvKZaQRs5AgtfUd3Nt1YoK0F0X3LPBunojQie1fN7PRihv3CJ5SAH55PGUwcygNNagX8vybeNsy7XfiRgJwUpWtuW3Be3NY5s2yArw53SUH_7Ce9fIGdl95kahXm6M_iNEk8UkLmBuZQtmGlYCRheF4OwWrdLaW5j6PBjJCjXJDaO8l4MLzUkRko1kyzn7025vF1OG6Ne3rjEmVcFvnEHLBeDEuta3aHI8eV03LLpOp_7cXQg-xuXXlIfmQl6dR5AMPDSQmuoUknHyWsnlFli3HACF-RcBw_dRYhie0nGbePqEdka5cWyHUuJ3pGPdwL-sAFQgSjZvNWLNRsHiayBQK4UV3eRBCjq0yNGM2qpFblNRzr0fbJTqKMpLztIz8Brwp1qNP1bJBENqzmcph4-glC9oZnz89XbS-6A=w359-h638-no)

(https://lh3.googleusercontent.com/S0ZkFzhKQk-oWmbuA7EpSG7yqXGRBgpecB0cJq4g3n4xYYjOtrrJxG4dWco4AWQJL91NbAEDNxCl02NQoZspYXOUeKaaS0U4SsvBUV9pBHgwiZPEWZHfQXYGS3UvLy7Jan-iX8V4TkDYiJefQuGHoHTAHBRh3kh3Pc6KgIOZXGhjh5HcXGDRFndqDgTY4m2aOfcjQ3aUvHbaI-thRTfx3lCqaqjAkPP--5cOID6-3hrCU1x6nOyV10WHp067DxHIkHRulstJSeoldf3tzbTCk41jYRT-Cl7SpY6FFDTZ1RzQbMKxV6lZBb7cSiZl0hTkznIIujODvxGwP_2YxXM69EltqB9gWFRE-lWpFqAv5-RkjoPiLy3Ii2F4kZU4z9tbfzPLIDa_5ujNtFEJ7WHxIeEpvisQUDfPzjUY4l7hNfJ7YJ7FFgWVjqIze05KD-rX7kNuc_fjbU7NsVIIUPl-5oRifGkN3JWNMLml8KIgBSPRmYhZ5KY6lSXBNuRF3WztEqW3QuIx5uk_KrvO9RMprIYCSdHh2lF8NyF95LKY14kokUdVy6BI8xzmvVo46GaMKUNl3ete2Mm2jUsOIjP-oBtW9KcmTvxlABIt3aEQc24KUS2moQ=w359-h638-no)

Title: Re: 372XP X-Torq Modding
Post by: ehp on November 04, 2016, 06:26:59 PM
OK this is just me and how I build saws, never ever build a saw without the base gasket , you guys have no idea on how many saws I have had to fix from other porters cause the saw has a huge air leak cause no base gasket . If its a cookie cutter that's fine but a saw that is meant to work there is no sealant that can stand the heat a loggers saw produces working everyday , it takes abit longer to mill the base of the cylinder compared to just deleting the base gasket but in the long run you end up with a saw that will not give you trouble . As far as gutting the stratos , I gut mine 110% , as far as tuning , my saws run very good and I'm most picky person out there on how my saws run
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 04, 2016, 09:15:58 PM
Quote from: ehp on November 04, 2016, 06:26:59 PM
OK this is just me and how I build saws, never ever build a saw without the base gasket , you guys have no idea on how many saws I have had to fix from other porters cause the saw has a huge air leak cause no base gasket . If its a cookie cutter that's fine but a saw that is meant to work there is no sealant that can stand the heat a loggers saw produces working everyday , it takes abit longer to mill the base of the cylinder compared to just deleting the base gasket but in the long run you end up with a saw that will not give you trouble . As far as gutting the stratos , I gut mine 110% , as far as tuning , my saws run very good and I'm most picky person out there on how my saws run

Yeah, I rarely run more than 2 tanks of fuel through a big saw in a day. I basically only cut a truck and trailer load of fire wood at a time, then split and load it. I am considering having Joe take it to his guy who already has the jug arbors set up, and having him take .020 off of it, or I may get my hands on a piece of round 2" stock and machine my own holder for machining 372 cylinders.

So gutting the stratos does make more power, or just make it easier to tune?

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 06, 2016, 08:19:02 AM
it makes more power , the bonus is it makes it easier to tune
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 06, 2016, 04:26:26 PM
Quote from: ehp on November 06, 2016, 08:19:02 AM
it makes more power , the bonus is it makes it easier to tune

Awesome, thanks! I'm going to do that, as well as widen the exhaust a bit. I saw 35mm up in the thread, as a max, so I'll go a little less than that.

Thanks again,
Mike
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 06, 2016, 07:20:33 PM
your numbers are pretty safe , My numbers are ALOT wilder that those numbers . I want my motors to pull in the 12500  to 12800 rpm range and when I say pull, I'm meaning my max horsepower is at those rpms . I ran my ported 365 today with just a 20 inch bar and chain, both brand new and had to push pretty hard on it to get the motor off the rev limiter from the coil . In a work saw I run the blue coil cause if it had the black coil the rpms would be a ways above 16,000 which puts a lot of stress on the crank and crank bearings that the crank does not need or want .
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 06, 2016, 10:32:31 PM
Wow, that's nuts!

I think I am going to cut the cylinder .020 and run the gasket. I've got a piece of 1.5" square rod that I can take the corners off of to the right size for it. I'll mess with that at lunch, tomorrow, out in the shop. Sounds like I'd have to adjust the port heights if I go any more than that, and I'm not sure I want to mess with the degree wheel and all of that, right now. I'm half tempted to take another .010 off of it and just raise all the ports by .020 and call it good, except I've already taken the Spike suggested .030 off of the bottom of the intake side of the piston, so I'm not sure about what that does. I've been working on 4-strokes since I was a kid, theory and all, but 2-strokes are pretty new to me.

Did this, this evening:

(https://lh3.googleusercontent.com/vn03Z75FakjNhCBvSw4cmmJ8bOdE8PBWzDptm9r66JoRHE_yI8siNdiRkZByzTG7MrCtl5MitnKJgXEO-iB4_U9deioHrWKv5QLM8EwtLKdGW5XWf2R4z2W6ilig4Pzk__nZ0JSO6mX57kaCYhY8lBwbjge-BbNnH-9zknrugCsM69zyHIwiZZ9AicqJX6rLWVXXCY84fHLlNLiJ7RFsg9VAgmH3uXCJQO7rv4Yc0XWcXxg8mfYyijRmf3bRFsjvpaXaCaNia_2eVjuaLFKAnwjoQWzWfmyhzwaVq8oaMLwGnENGndWG7R-5vUVQH0zUomRTuEE82rw7FjQk6TxdkAu_WpvX_8_e2IAd_FmzeEDOK8TyvU39neNzSwExSsPGNdImE8Rt7vmFwg3Elnm_v2cXxfE8-xt2rpgLiuyhamaISonAD1ffR24MOXgFLEgO1MBcmgxxGwA2Yy1t0li61hqSdf3EkxvNlynuejxq6kCdbemg-1MDq5k-S0Nu3ZLPaklUzTiJFfRDH-i3weAYbl86oQjb5jyrkgD_NjEG6vk18crVPIUvcWhqcZgzrKKFdYZIDCbCuXX8UX5v3h7IKdsNpCCmy0qyAgt8EoeK5E3hJau2Nw=w359-h638-no)
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 07, 2016, 11:31:56 AM
From another thread, I think I've seen that as you lower the jug and do a woods port, you end up opening the intake port lower and the exhaust port higher... So, since I'm lowering the jug and took .030" off the piston skirt, the only thing left to do, height-wise, is raise the exhaust port a bit? .020 or something?

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 07, 2016, 07:05:19 PM
there is a lot more than just that to do, this is just me so whatever , I never cut the intake skirt on the piston  EVER. Your doing a port job so port the ports , not take what most think is the easy route and cut the skirt , the intake skirt is abused far many more times than the ext skirt  . Look at how the crank turns over in the engine , on the up stroke the rod is pushing on the piston towards the intake port hard so the piston needs every bit of its material to help the skirt from  first wear, next is cracking and if you cut the skirt far enough you will end up with the pattern shape of the intake port right in the skirt of your piston, seen that lots of times . You lower the jug to raise compression so your already increasing your intake port timing . Now you go ahead and cut the skirt to increase more intake port timing but one thing , when the piston travels to TDC your piston skirt on the bottom is going to travel past the top side of your intake port so your going to get a false port timing number cause most guys donot raise the top of the intake port to line up with the bottom of the piston skirt at TDC. Even without cutting the skirt you need to do that cause you lowered the cylinder to raise compression . Now as far as porting numbers go , if you lower your cylinder were just going to say .020 and you raise you ext and transfer ports .020 you just made a stock porting motor that has more compression , yes it will rev abit higher than stock but that's mainly cause you increased the compression and you muffler modded the motor . Its pretty easy to make a motor that has more power that stock, what is not so easy is to make a engine that has quite abit more power than stock but last every bit as long as a stock motor and in lots of cases out last the stock motor cause the stock motor runs way to high of temperature inside the engine which causes most new saws engine failure . Now like I said this is just me and my way of doing things
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 07, 2016, 08:04:43 PM
Quote from: ehp on November 07, 2016, 07:05:19 PM
there is a lot more than just that to do, this is just me so whatever , I never cut the intake skirt on the piston  EVER. Your doing a port job so port the ports , not take what most think is the easy route and cut the skirt , the intake skirt is abused far many more times than the ext skirt  . Look at how the crank turns over in the engine , on the up stroke the rod is pushing on the piston towards the intake port hard so the piston needs every bit of its material to help the skirt from  first wear, next is cracking and if you cut the skirt far enough you will end up with the pattern shape of the intake port right in the skirt of your piston, seen that lots of times . You lower the jug to raise compression so your already increasing your intake port timing . Now you go ahead and cut the skirt to increase more intake port timing but one thing , when the piston travels to TDC your piston skirt on the bottom is going to travel past the top side of your intake port so your going to get a false port timing number cause most guys donot raise the top of the intake port to line up with the bottom of the piston skirt at TDC. Even without cutting the skirt you need to do that cause you lowered the cylinder to raise compression . Now as far as porting numbers go , if you lower your cylinder were just going to say .020 and you raise you ext and transfer ports .020 you just made a stock porting motor that has more compression , yes it will rev abit higher than stock but that's mainly cause you increased the compression and you muffler modded the motor . Its pretty easy to make a motor that has more power that stock, what is not so easy is to make a engine that has quite abit more power than stock but last every bit as long as a stock motor and in lots of cases out last the stock motor cause the stock motor runs way to high of temperature inside the engine which causes most new saws engine failure . Now like I said this is just me and my way of doing things

Hmmm... OK, thanks! I really just cut the .030 off of the intake piston skirt because that's what this thread said to do to "farmer jones" it, along with ditching the gasket. However, I am going to take .020 off of the cylinder base and use the gasket, per your post above and how Joe (elect) did my 371XP port job. I'm tempted, now that i'm making the fixture for the jug, to take .030 off (and make the popup .010 taller), but I'm concerned that with the .030 I've already taken off the piston skirt, that's going to be too much intake timing??

Also, I'm curious about what the false intake timing does, when the skirt is above the bottom of the intake?

If I have to buy a $40 piston, I have to buy a $40 piston... Not a huge deal. This one has already run some production, I'm pretty sure (even though it's a 2015 saw), because it's missing the machine marks on about 1/2 the skirt area, and it not super-smooth on the transfer side. I'd just rather not buy a jug, obviously...

On the exhaust timing, taking it back to stock time, I've got the blue coil anyway, and this being an XT and my other ported saw being the 371XP, I want to keep a 20-24" on the 371 and have the XT be the one I run longer bars on. Because of this and the coil, I'm not sure I want to move exhaust timing up too far, and get rid of some of the wide power range?

Thank you again for all of your knowledge and time/help, as I'm picking this up!

Mike
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 07, 2016, 09:44:58 PM
As an aside, gutted the carb and intake dividers, this evening, as well as did the muffler mod, the same as I did on my 371XP.

(https://lh3.googleusercontent.com/p3PRVsXSMO2qc6WWgGo4dgJn54rZE6xVei8SjpaeFPFaJ3b_Lmv5VPutfPnp6ZBow07Os3dKI88=w553-h638-no)

(https://lh3.googleusercontent.com/Mn2IYigwCKj6GORkDZLYYSgO2xSpJTTWczPBWgzj_KHOXbnWFyWRpSPz7akj2YHu60RI5myRm3g0f1ejCIstTGDvfDSd1O6JcpCXKS7cYvzMG_SfqEv1FrLjbFyRGiJfwlFT_pujW8qYFeo3lGAjFk4AK4mK4h6bicCeFaAbuRfpnBVuJy3y4O5VHPnWr628RVeDaCR1ab29wCzuz9d45XLOlpjQKoYRhgVnw9vxf9F72Nn14jUMc6a20PdF0CdA4NZLpobLTI9vFlusSvCklJc6zBSRgPfp-jhc1RombN1pIKE7YYNvnWftImxHuyGBfb19oyGzb4up5wjzZYYblWlK4DczKxp-cK7bz0MRzYdB7yhxffojzzJ7aKYB_9SG19AyfHo8sQSi14QEW4wM7MDET6oi8R0FDVpqB4ntUG63wVT1jso5ASLAE-hAboxl5li-2icz_9WooWGjSIHz3IcqBfR3qHeZSGQ9YyxSvzqLtvIkdX42wFiPG_TMljau9TpeREE2v_uSYIYU1Mc2OeErN9S9bCfPXgVFb0lXAgP-73hXxOlh4-GUXX3jjjODmsUJdDtNxwporyPntDY0YzGaS2NJIw09ZLFCxLsYGVo70x5SZQ=w1135-h638-no)
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 08, 2016, 02:26:55 PM
Ready to take either .020 or .030 off the cylinder, depending...

(https://lh3.googleusercontent.com/i5j3WuIw82TAEuDUx0QUIKn4wyVRpzcnY16Dfh9HWkt_0ES0rwi2ngfjG8OR5pOqtfimEFi1SwrPwVYiVK53G8Gsv4Nv2FKXr3ipguCpbwB2fq0vfby13v05HByLV81icjyb-C8djdx3CBUL6my_TqwYEXLVlX0lUdzdOtvcRNDAuulrL58a2M2SS4XPCXbFISnRu4iueD5HreYx9DBQA0T72fYd9yORCIbgJ542MKO9Q4Pkog0Tc9Yq-jroMnuPv1cNK4agrQT8XHiJd-1Cbst7TOh6WrxLbPTLV7bUJPuKrsFakzD1kNlEHqNa8n43wMt4sw8C8786RCK8XvkhNlpN-WSYBtbuVGFB6YbWZGxYRjGTOOM-5uOGfQJk3lJBsRZ3jEnWvqBiB7FTodSL32K5QeKwNUDN3zPrJe9-td6_PsiGFPSZ1-I6hM6KO0NhgEOu2Eor8nl-85vhXpiCdChHZTLZJTl8QVP6_vKRnyARntIwMrlOeHwfFuskWDMMUHjNrWFTNDrng6BXfDTUniKO3PhZWdlQ7ccfIdoYm-QfVjf2pcq-lKSp1GKkAPmj6MbbzuGJTVFpzGS_P_rLMihbKEv7T0uS4pnCKORRryD0VGlzQg=w1247-h701-no)
Title: Re: 372XP X-Torq Modding
Post by: Wildman Ben on November 08, 2016, 04:38:56 PM
So I don't have the means to deck or machine the piston and I'm leaving the base gasket there as its heavily used as a work saw, Will removing the dividers from the boot and carb then grinding out the intake port and between the strato ports and widening out the exhaust side of the exhaust port (following the pictures back on page 8) will that give me noticible gains? or should I widen the exhaust port / intake port on the piston side a little bit aswell?
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 09, 2016, 06:18:48 PM
you have to think of port timing this way, all port timing is for is to move air through the motor . You do not raise the roof of the intake port so its level with the bottom of the intake skirt when the piston it at TDC your not using the full port area cause its not open yes below is open but that's not the complete port , another thing you need to think about is this if you cut the bottom of the skirt say .030 then you need to watch raising the roof of the intake port cause you can end up with the lower rings on the piston in the intake port . You need to measure all that kind of stuff before you start grinding to make sure your not going to end up with a door stop or paper weight . This point has to be checked very close if you stroke the motor and some guys do , Single ring pistons work far better for this type of motor if stroking .
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 09, 2016, 06:23:56 PM
Wild, if you port your intake and ext. port but donot raise over compression your loosing a lot of the power the motor should be making , You are going to lower the compression with porting . If it was me and you have no one that can cut the base of your cylinder . I would gut the stratos and muffler mod the saw , that will give you the most bang for your buck without porting . Play with the jets on the carb , there is a lot of power in these motors but you got to get the carb set proper
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 09, 2016, 10:25:17 PM
Quote from: ehp on November 09, 2016, 06:18:48 PM
you have to think of port timing this way, all port timing is for is to move air through the motor . You do not raise the roof of the intake port so its level with the bottom of the intake skirt when the piston it at TDC your not using the full port area cause its not open yes below is open but that's not the complete port , another thing you need to think about is this if you cut the bottom of the skirt say .030 then you need to watch raising the roof of the intake port cause you can end up with the lower rings on the piston in the intake port . You need to measure all that kind of stuff before you start grinding to make sure your not going to end up with a door stop or paper weight . This point has to be checked very close if you stroke the motor and some guys do , Single ring pistons work far better for this type of motor if stroking .

Thanks! I actually went ahead and just went ahead and with the plan to take .020 off of it, today, and I'm going to put it back together like this (gutted strato intake, beveling/blending the transfers, .030 off the skirt, .015 pop-up and .020 off the cylinder for .022 squish, and opening up the exhaust outlet a bit and muffler modding it), then I'm ordering a degree wheel, finding a good deal on a CC right angle grinder, and researching, researching, researching how to port, what the numbers do for intake/exhaust, etc... THEN I'll dig back into it once I know what i'm doing, and do it right, rather than just half-ass trying to guess at something approximating a decent port job.

(https://lh3.googleusercontent.com/SKL7pUxe0YT8dCOLQ6ckShaWGkuKjecUkwCm31JyUacJqH-9Ykf2xhDGAYNC9pvz-YhdspIPU2wToyAEyic70V51UK0qBauNG-D54x6h3p3OgD9Qa4xNLxPGnnPfjBIN8mKmhI5Ros6icQfzb8n6MgnnNqHhTWqqJoQFki6F6y5JtDs_1zVZiD9KpqDMLN8DKoliIbc_cTbj5hw57WsAFHcmmoM9OLfzFLEmCnv0w1Pg77ysRg3kYg5Ad93mdveC9mo8JVKsk7JB1H-0SDuBx66W-S_Z6Bk8_ieK27dcjt2dDoo7t8_BqI6NY683iK0-TBgvOYMxbbx2qEPVV9YEoD7_qrO4rePN12c2VMxTc0G9HFxMdPggfJClGr-wJYn9RJD2xqqycfZ29dh83tVdWB9dV-1VQxKVR4qqMJYZJUjPvvvhqXzpdZLLbXryeg6eEgaSr2wptcldn1bG7PBHFCBy1eGumOu3Dpha8rFcTxqPStfRJlyI-xVNv2SMl6QTlMncdRX6wYPAWSayK2TtoXMIJLmNF9ge0ILNlYmUorvKJj1Jrk6AlOiufZxiNkWxoewKoW394bIzo5MNQCW0EWXV5xJZRkDVsJ1y65ZiqYD8znPgGQ=w359-h638-no)
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 10, 2016, 07:06:20 PM
your going at it the correct way, first thing never believe everything you see on the internet , next do the math and figure out what the motor wants , pretty much every different motor needs different porting numbers , You will need to learn how to figure out crankcase volume , that part is a must if your going to build a motor and not be trail and error . Ya buy the 90 degree from CC, the foredom 90 degree is not much good , they break pretty easy
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 10, 2016, 11:03:41 PM
Quote from: ehp on November 10, 2016, 07:06:20 PM
your going at it the correct way, first thing never believe everything you see on the internet , next do the math and figure out what the motor wants , pretty much every different motor needs different porting numbers , You will need to learn how to figure out crankcase volume , that part is a must if your going to build a motor and not be trail and error . Ya buy the 90 degree from CC, the foredom 90 degree is not much good , they break pretty easy

Awesome, thanks! Any good books or resources for "how to port a 2-stroke" and stuff?

BTW, got the saw back together tonight, but since it's nearly 11PM on a "school" night, I haven't started it yet. Probably Sunday afternoon when I get back from hunting.

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on November 19, 2016, 04:29:17 AM
Looking forward to hearing your saw run.  To answer your initial question I am very happy with my saw still.  Following ehp's guidance turned it into a formidable 372.  Glad you found this thread helpful.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 22, 2016, 10:04:01 PM
Quote from: XP_Slinger on November 19, 2016, 04:29:17 AM
Looking forward to hearing your saw run.  To answer your initial question I am very happy with my saw still.  Following ehp's guidance turned it into a formidable 372.  Glad you found this thread helpful.

Awesome!

It'll be a week or 2 before that happens. I got it back together, but it'll idle for like 10 seconds fine, then it'll lean out and die unless I rev it. I can rev it or run it, then idle it for 7-8 seconds fine, then if I don't rev it again, the rpm gets shaky and raises like you're running out of gas, and it dies. One of 2 things happened. When I was grinding out the limiting screw stop, I got a piece of plastic down in the idle circuit that I can't get out even with spraying air and/or carb cleaner all directions; or the thing has had enough E10 run through it over the last 2 years it's been alive that the diaphragm is a bit stiff and it doesn't want to pull fuel while idling. I haven't done a pressure/vac test on it, but it really seems like a carb issue, to me. I've got a carb kit on the way, anyway.

Mike
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on November 24, 2016, 04:37:01 AM
If you weren't able to tune out the lean condition with your jetting adjustments I'd say a pressure test should be the first order of business.  Hopefully you didn't cut a hole in the intake boot while you were removing the strato dividers.  Best of luck
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 24, 2016, 05:46:51 PM
I would say you got a air leak but there is another thing you need to check on these 365/372 xts, the fuel line is terrible in these saws and they get a hole in the line right where it comes out of the fuel tank , if you have never shorten the fuel line , pull line off carb and pull up easy on it and right where it goes threw the tank look real close for a hole , cut the line off at that place where it goes threw the tank and put end back on carb , the line is long enough in the tank to do this . I have changed every fuel line in my xts and is the only saw I have to do this to , some xt's I donot get 4 months out of it before having to change the fuel line
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 24, 2016, 09:30:06 PM
Quote from: XP_Slinger on November 24, 2016, 04:37:01 AM
If you weren't able to tune out the lean condition with your jetting adjustments I'd say a pressure test should be the first order of business.  Hopefully you didn't cut a hole in the intake boot while you were removing the strato dividers.  Best of luck

I can actually make it way rich (so much that it loads up at idle) with the adjustments, at least for the first 8-10 seconds at idle, then it leans out and dies. I can get it running right and idling right, as long as I don't just let it sit and idle for more than like 8 seconds between revs.

Quote from: ehp on November 24, 2016, 05:46:51 PM

I would say you got a air leak but there is another thing you need to check on these 365/372 xts, the fuel line is terrible in these saws and they get a hole in the line right where it comes out of the fuel tank , if you have never shorten the fuel line , pull line off carb and pull up easy on it and right where it goes threw the tank look real close for a hole , cut the line off at that place where it goes threw the tank and put end back on carb , the line is long enough in the tank to do this . I have changed every fuel line in my xts and is the only saw I have to do this to , some xt's I donot get 4 months out of it before having to change the fuel line

I will check the fuel lines, as well, thank you. I'll also eventually do a pressure/vac check, but I can only do a vac check with my mighty-vac. I need to figure out some way to do pressure, as well. I also need to figure out what to use to block off the intake and exhaust.

Thanks
Mike
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 25, 2016, 06:54:36 AM
get yourself a can of WD-40 with the straw part on it , set carb so saw will idle the longest you can, take the top covers off saw and have spray can ready , start saw and spray intake boot and around base of cylinder and transfer port doors with it running , if you got a air leak in these areas the saw will quit as soon as the wd-40 finds the hole , its fast way to find air leaks and it does work
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 25, 2016, 10:00:09 AM
Dropped in as it looked like there was activity, have my "decked" (with the lathe) Huztl XT cylinder build about ready and assembled with 1184 out of shear defiance...:) The flange/"rib" at the lower transfer port area thickness is really what had me "split" the difference between lathe work & no base gasket to get what I wanted...but defiance sounds better. ( .018 squish, Intake 77 BTDC,  exhaust 100 ATDC, blow down 20 degrees. Gutted filter holder & boot. Muffler mod. left divider in the carb. Worked the "divider" on the intake to favor the case, raised the intake to match the  skirt at TDC, blended the lower transfers, etc. The Huztl AM cylinder has half the x-sectional area in the "X-Torq" channels where it intersects the cylinder wall..curious about how that will effect things. Had to raise the exhaust quite a bit. STILL don't like the transfers where they enter the cylinder, and how much lower they are relative to the top of the piston when they are opened at BDC....so widened them towards the intake side some. ) Cautiously optimistic. Just finished a couple OEM versions that run really well. Had this Huztl for a while. Needed a purpose, so its now a crash test dummy. No pics or vids  until either it grenades and makes a good bang or has lasted long enough to be worthy.

Sounds like this "tuning" issue is well covered by those who know that saw and build inside out! .... ehp's wd40 is a good "leak" detector. I've also used the non flammable brake clean products as they will stop that saw like an on/off switch when you find that spot when the "safer" wd wasn't in the shop. 

I had a saw once that would start on choke "OK" run and cut OK. Would drop right to an idle when the throttle was released after a cut as it should ... then idle nice for a few seconds then quit with a lean condition..rev up a bit then stop. Real Pita. First thought was carb diaphragm,  then compression (Except it STARTED), of course explored the leak concept....Turned out to be a kinked therefore partially blocked pulse line. When choked...got enough fuel to get started...at RPM's there was enough pulse strength often enough through the "kink" to supply fuel at RPM's....and at idle it didn't have enough to keep that carb full, hence the stall. An old Jonsered. It ran a whole lot better once that was set right. Puzzled on it for a while after fixing it, Realized that it would be *DanG near impossible to replicate that!

Actually I've fixed a few really erratic running X-torq's where the plug wire was arcing to the cylinder at the top couple of fins. Presents in all kind of ways to just confuse every one, and often not the same way from saw to saw. If After all the other more reasonable diagnostic approaches still produce frustration...look there. A solution is to cut a 1/4 inch or so off the corners (Just the corners!) of those  fins and make certain there is a clear 1/4 inch or more between the wire and the cylinder fins. That spot on the top cover holds that wire usually but especially on the older ones with a ton of hours they seem to lose the grip and let that wire wonder towards frustration.   Saw four or five of that from the 2012 era saws this last year or so.

Also rebuilt a few where the clutch side crank case bearings ate their nylon cages then chucked their balls into the motors.. now THAT presents first as an air leak at idle when the  cages fail and the crank wobbles a tiny bit being hammered by that taller / heavier than OE piston therefore more intense vibration. If not dealt with then; catastrophic failure. By the time that particular "leak" event effects normal running....start looking for metal. I've gotten to the point where if you have an older 372X-Torq with some time that has those bearings. Change them. And I don't care what the experts say. Just seen too many go through the shop....the MOST common repair I've seen other than crash damage from the loggers I support.

What that looks like:
(https://forestryforum.com/gallery/albums/userpics/11485/20160717_103626.jpg?easyrotate_cache=1480097740)
(https://forestryforum.com/gallery/albums/userpics/11485/20160717_094805.jpg?easyrotate_cache=1480097690)

Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 25, 2016, 03:02:31 PM
Back to X-Torq. So now that the X-Torq channels are going to be full of mix....do we really care if the piston's channel gets exposed to the crank case if it's not going to bleed pressure into a bad place? Does that give latitude to work on that cylinder skirt? How about the intake port ... as the piston channel travels around half way down  the intake port, the other end passes the transfers & is closed....can we just widen that lower part of the intake port? Even though it now exposes the channel? Just asking... might just kill a Huztl cylinder or three to quantify the gain same or loss...Also considering the concept of simply plugging the X-torq passages from the intake port side.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 27, 2016, 12:16:24 PM
OK, so I looked and the pulse line isn't kinked. The fuel line was OK (though rubbing thin in one area, where it pivots inside the tank), but I did notice that the fuel tank holds pressure. I went to check the vent line, and the vent was unplugged at the tank, for who knows how long. I supposed I should replace this vent, being that seems like it's plugged. Probably not my main issue with the idling, but still should be changed, I suspect.

(https://forestryforum.com/gallery/albums/userpics/44237/IMG_20161127_112412095_HDR.jpg)

I'm also going to just replace all the fuel/vent lines while I've got it opened up. I know I can get them from Husq, but are there better lines to run? Also getting a new fuel filter, just because.

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 12:28:01 PM
Tank vent being restricted actually could present similar, but also would make things lean when cutting as well. But that's easy to check, get it fired up, put the chain brake on. lay it on its side & open the gas cap.....if it idles happily ever after with that open you found your boggle. Did you try to squirt some WD or Brake clean in the clutch cover to see if it shuts the saw right down at low RPMs (Chain Brake ON!) ? If you get an ambiguous result....pull that cover and B&C right off and then try again. If it does show a response, be thankful you found that now! And if it doesn't be thankful about the hassle you don't have to deal with! A "win win" situation. And if spray around under the clutch cover does nothng then try right around the intake boot and the base of the cylinder .. and don't be afraid to pull your cover when hunting for leaks with a spray can. Just do that wen you found a general area with the covers on...then can pull the cover for more access. Obviously you don't want that saw running long without it and therefore less air flow for cooling...just to hone in on suspected area.

Spray can diagnostics doesn't work well on the flywheel side with the covers on...that "turbo" Jonsered inspired feature sends it right to the air box...then the carb....and you get a false impression

But please over analyze that clutch side bearing / seal and if there are symptoms don't just replace the seal, get that bearing out too. Rather you be *pithed at me having you chase a ghost than have a bearing failure wreck a saw.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 27, 2016, 12:42:11 PM
Quote from: weimedog on November 27, 2016, 12:28:01 PM
Tank vent being restricted actually could present similar, but also would make things lean when cutting as well. But that's easy to check, get it fired up, put the chain brake on. lay it on its side & open the gas cap.....if it idles happily ever after with that open you found your boggle. Did you try to squirt some WD or Brake clean in the clutch cover to see if it shuts the saw right down at low RPMs (Chain Brake ON!) ? If it does, be thankful you found that now!And if spray around under the clutch cover does nothng then try right around the intake boot and the base of the cylinder .. and don't be afraid to pull your cover when hunting for leaks with a spray can. Just do that wen you found a general area with the covers on...then can pull the cover for more access. Obviously you don't want that saw running long without it and therefore less air flow...just to hone in on suspected area.

I haven't done the WD / brake clean thing yet. I was messing around with fuel/pulse/vent lines and found the unplugged vent line and started chasing that. I also have a vac/pressure tester on order, just to have. I also need to figure out what to use to block the intake and exhaust? Some 1/8" rubber material or something?

Also, any ideas on replacement fuel lines? OEM or others better?

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 12:59:09 PM
On all things rubber, when in doubt go OEM. Actually on all things if in doubt go Manufactures recommendation!

Did you try the "gas cap" deal??

For vac testing Husqvarna actually sells the "plugs" for exhaust and intake. I used a piece of "tractor supply" flat stock and a cut up tire tube for the exhaust. I have the intake side plugs so didn't have to innovate but yet again a plate between the carb and  intake is a possibility with your skills.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 01:02:15 PM
Just all that is going thru a LOT of effort when you really can get a sense with a spray can and other simple things. I use the vac test more to check my builds than in analysis actually be cause with a little history on those saws and some simple tests like we discussed you can find most of what ails them.

Add to what ehp said about fuel lines, my "history" with them when the problems were tough to find usually ended up with the spark plug wire too close to the cylinder, bad carb, or bad clutch side bearing to the point if I see a 2012 era 372 I go to the plug wire first and that bearing second JUST to eliminate them up front so I don't have to WORRY about them..:)
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 27, 2016, 01:22:40 PM
I haven't done any other "running" tests because the saw is apart and I don't have any wood to cut for a couple months at least, and if I do, it's not like I don't have other saws I can use. I'll put fuel lines on it (order them) and the vac/pressure test tool will be here, as well. I've got OEM bearings/seals for my 1999 371xp that it didn't end up needing, so I'll need to check and see if those cross over. It's a 2015 2166, but I'm pretty sure it was used in production or something, because while it looks good, the piston has the machine marks worn smooth, and the rim sprocket has a pretty decent amount of wear on it. If there's any leak around the crank seals, I'll just tear it down and do bearings so I don't grenade the thing.

Mike
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 01:52:51 PM
2015 era should be ok but I just get paranoid with those saws and check anyway, and if there is an issue those 371 Bearings & Seals should work. Just need "metal" caged 6202 c3's

Husqvarna plugs:

(https://forestryforum.com/gallery/albums/userpics/11485/20161127_133321.jpg?easyrotate_cache=1480272609)

(https://forestryforum.com/gallery/albums/userpics/11485/20161127_133151.jpg?easyrotate_cache=1480272620)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 06:37:16 PM
Had to rob parts from my pile of junk 385's, one of them sacrificed the chain brake internals. Another 372 sacrificed its handle. Took an old 385 muffler that had a vibration crack all across the from then down under the was in the scrap pile. Brazed it up an plugged its original outlet and made another.. Took a carb that was known to be a little goofy from a box full of carbs in the back of the shop...they were headed to the scrap pile. I put new rubber in in and slapped it on this Huztl X-Torq. Put a Chinese ignition....tank handle, pull start, side cover, at first I thought it had an air leak. JUST before tearing into that I realized the cheap throttle cable was so stiff it wouldn't let the throttle close. So when I pushed it closed it sat and idled. Had to turn the carb adjustment screws way out. Two turns on idle and to keep it around 14k 1.75 on high. It did respond to those adjusters.. And would drop right to idle when I pushed the throttle closed. Longer it ran the smoother it got and then began to require me to take 1/8 turn in to stay idling and stay at 14k. It sounds kinda of funny. Jumps right to top rpm, just instant throttle response because I doesn't have a load yet.

Wondering if maybe it makes sense to blend a WJ 118 or one of those old 385 carbs to this saw. I have ten or so old 385 carbs. Not sure of their future...maybe this saw might be salvation from the scrap pile for one.

Where I set the high...a little more than 1.5 turns out & just a little "4 stroking" rap.
(https://forestryforum.com/gallery/albums/userpics/11485/20161127_175108.jpg?easyrotate_cache=1480288475)

Where idle ended up at 1.75 turns out
(https://forestryforum.com/gallery/albums/userpics/11485/20161127_174816.jpg?easyrotate_cache=1480288457)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 06:45:07 PM
Some pics of yet another "ugly" saw build made from primarily Chinese and scrap parts. The bottom end is solid, "Nachi" brand bearings and OEM seals. But everything else is junk...:) But it runs. AND it holds vacuum BTW. Even though it has 1184 as a gasket...the question is for how long.. :D

It's on the left....a few details.....needs the plug wire shortened, top cover, really needs a fresh carburetor!
(https://forestryforum.com/gallery/albums/userpics/11485/20161127_165708.jpg?easyrotate_cache=1480288461)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 06:52:12 PM
Muffler

(https://forestryforum.com/gallery/albums/userpics/11485/20161127_143707.jpg?easyrotate_cache=1480290467)

Muffler mod!
(https://forestryforum.com/gallery/albums/userpics/11485/20161127_143718.jpg?easyrotate_cache=1480290470)

Paint!

(https://forestryforum.com/gallery/albums/userpics/11485/20161127_151041.jpg?easyrotate_cache=1480290504)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 06:55:31 PM
Kind of like an old dog rolling in cow crap, walking into the nice clean house and shaking it off, isn't it! But it has that initial feel to be a strong build.....we will see. Think I'm going to compare it to the Huztl 52mm build I did, then go back in and gut that intake and cut those skirts. :)

I might have a bit more than $200 into that saw. The only things I paid for was the original 2166, $80 bucks. The bearings & seals. And the Huztl plastic & $60 dollar top end
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on November 27, 2016, 07:43:29 PM
Glad to see you're experimenting with the XT again bud.  Anxious to see how your "dog covered in cow crap" runs... :D. I bet it will be impressive.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 09:16:45 PM
Not sure how impressive! But its been an adventure. But so was Cyclops, the Huztl 52mm saw this will replace...that other is in retirement.

Have a bug or two to work out. The carb's throttle return spring can't overcome the cheap AM throttle cable so it doesn't shut all the way unless I go and push it shut....and when it does, it will sit and idle nice and steady at around 2600. Also I feel as if I'm at the limit of what that carb can do. I maybe wrong but it feels like It could use a little more fuel up in that high rpm under load. I set it around 14,200 as that's when it begins to "four stroke" rap a bit. Then set it to 13,700 and its past 1.75 turns out. Also I don't have much faith in that AM ignition...:) but I think its ready for some wood to see where it sits in the stack. Investigating if a WJ 118 might be a good move.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on November 27, 2016, 09:24:15 PM
Quote from: weimedog on November 27, 2016, 09:16:45 PM
Not sure how impressive! But its been an adventure. But so was Cyclops, the Huztl 52mm saw this will replace...that other is in retirement.

Have a bug or two to work out. The carb's throttle return spring can't overcome the cheap AM throttle cable so it doesn't shut all the way unless I go and push it shut....and when it does, it will sit and idle nice and steady at around 2600. Also I feel as if I'm at the limit of what that carb can do. I maybe wrong but it feels like It could use a little more fuel up in that high rpm under load. I set it around 14,200 as that's when it begins to "four stroke" rap a bit. Then set it to 13,700 and its past 1.75 turns out. Also I don't have much faith in that AM ignition...:) but I think its ready for some wood to see where it sits in the stack. Investigating if a WJ 118 might be a good move.

Did you advance the timing at all?  If not, that may help with your top end power.
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 09:35:37 PM
No haven't messed with timing yet, just wanted to get it running and "debug" both the chassis and motor to where I have a solid test bed to work with. Its ok right now. I think its a fast bakery (cookies) but I'm not certain it has the grunt I like. Won't know until I run it for a few tanks to tweak and break in.

This saw literally built from scrapes around the shop, some 372, some AM, some 385. All were headed out to the trash as I won't use the stuff on saws that count. :) And I need to clear some stuff out...we are ripping the roof and trusses off right to the walls and building a new structure to more "formalize" the shop.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 27, 2016, 09:55:02 PM
These bearings are good for this 2166, correct?

https://www.amazon.com/gp/product/B006316MES/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 27, 2016, 11:49:31 PM
Yup and they are a rather significant upgrade I might add...
Title: Re: 372XP X-Torq Modding
Post by: barton174 on November 28, 2016, 08:15:58 AM
Quote from: weimedog on November 27, 2016, 11:49:31 PM
Yup and they are a rather significant upgrade I might add...

Yeah, I saw there was a 14krpm model and a 26krpm model, and they're about the same price, so makes sense to get the 26krpm ones.

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 28, 2016, 09:44:36 AM
Quote from: XP_Slinger on November 27, 2016, 07:43:29 PM
Glad to see you're experimenting with the XT again bud.  Anxious to see how your "dog covered in cow crap" runs... :D. I bet it will be impressive.

Actually it will be impressive if it compares favorably with those "OEM" saws....why?? Lets review:

Huztl AM Cylinder & Piston.
"No Name" AM ignition
Smashed 385 Muffler
AM plastic, rubber parts like fuel lines, carb kits, and air filter.
OK crank from a blown up saw.
NO gaskets, just goo to seal up the top end

SO using "conventional" logic this *DanG saw shouldn't run! And if it does, not for very long. SO my goal was to split the "performance" difference between "work build" saws done with good parts and a stock saw... If we do as well as a "OEM Work Build", AND it lasts long enough to make it to my saw retirement home and not the trash; that's going to be on the border line of impressive.  :)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on November 28, 2016, 02:40:27 PM
Cheap ignition lasted 1/2 hour and died, why it was in the junk pile because that's been a predictable thing with those cheap things. Put an "OEM" black one in. No idea what it came out of. Spliced a longer plug wire...and the saw runs better....everywhere.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 13, 2016, 09:12:43 PM
Well, I got the 2166 back together. Put a carb kit in it, fuel line and filter on it, and tank vent on it. It vac and pressure tested great. (I also put a felt filter on it) It runs really well, and idles well, but now waits until 20 seconds at idle to lean out and die, now, instead of 8-10 seconds.

I can suck and blow on the pulse line and it seems as open as it needs to be.

You guys are running without the plastic separator in the carb, between the throttle and choke butterflies, right?

I wonder if taking the .030 off the piston skirt intake side makes it just not make enough vacuum in the crankcase to work the diaphragm enough at idle to pump in enough fuel to the carb? What makes me think that is the issue is the carb kit (more pliable, easier working diaphragm) doubled the time it takes for the bowl to run dry on fuel.

Thoughts?

Thanks
Mike
Title: Re: 372XP X-Torq Modding
Post by: weimedog on December 15, 2016, 11:12:31 AM
Quote from: barton174 on December 13, 2016, 09:12:43 PM
Well, I got the 2166 back together. Put a carb kit in it, fuel line and filter on it, and tank vent on it. It vac and pressure tested great. (I also put a felt filter on it) It runs really well, and idles well, but now waits until 20 seconds at idle to lean out and die, now, instead of 8-10 seconds.

I can suck and blow on the pulse line and it seems as open as it needs to be.

You guys are running without the plastic separator in the carb, between the throttle and choke butterflies, right?

I wonder if taking the .030 off the piston skirt intake side makes it just not make enough vacuum in the crankcase to work the diaphragm enough at idle to pump in enough fuel to the carb? What makes me think that is the issue is the carb kit (more pliable, easier working diaphragm) doubled the time it takes for the bowl to run dry on fuel.

Thoughts?

Thanks
Mike

Is that the same carburetor & ignition through this entire time? doubt the .030" more intake is going to do much to effect the idle, even when combined with the .020" for a no base gasket build for a total of .050" or effectively opening approx. 2.5 degrees BTDC.....I've lowered the intake port on one of mine more that that, and the intake port on that goofy Huztl cylinder way more than that when you figure in the .030 I took off the base of the cylinder. If I remember, you have at this point changed or checked pretty much everything rubber from fuel line, fuel filter, to pulse lines. Tank vent and all related things. Assuming you checked things like the fuel line for being pinched somewhere between the handle and the carb etc.. and that the filter stays down in the gas when you have a partial tank full.....and I assume you checked the plug wire for grounding on the fins...that presents like a lean condition. AND you checked the seals with vacuum testing. Also assume you checked the pulse fitting and passage to be absolutely clear. With those assumptions, To me its got to be in the body of the carb, the low speed circuit somewhere and this is supported by your observations relative to the carb kits.. Or its ignition. Thats it. One or the other. Actually I have the separator in my carb, I guess that could be an issue but others seem to do fine without it.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 15, 2016, 12:26:32 PM
Quote from: weimedog on December 15, 2016, 11:12:31 AM
Quote from: barton174 on December 13, 2016, 09:12:43 PM
Well, I got the 2166 back together. Put a carb kit in it, fuel line and filter on it, and tank vent on it. It vac and pressure tested great. (I also put a felt filter on it) It runs really well, and idles well, but now waits until 20 seconds at idle to lean out and die, now, instead of 8-10 seconds.

I can suck and blow on the pulse line and it seems as open as it needs to be.

You guys are running without the plastic separator in the carb, between the throttle and choke butterflies, right?

I wonder if taking the .030 off the piston skirt intake side makes it just not make enough vacuum in the crankcase to work the diaphragm enough at idle to pump in enough fuel to the carb? What makes me think that is the issue is the carb kit (more pliable, easier working diaphragm) doubled the time it takes for the bowl to run dry on fuel.

Thoughts?

Thanks
Mike

Is that the same carburetor & ignition through this entire time? doubt the .030" more intake is going to do much to effect the idle, even when combined with the .020" for a no base gasket build for a total of .050" or effectively opening approx. 2.5 degrees BTDC.....I've lowered the intake port on one of mine more that that, and the intake port on that goofy Huztl cylinder way more than that when you figure in the .030 I took off the base of the cylinder. If I remember, you have at this point changed or checked pretty much everything rubber from fuel line, fuel filter, to pulse lines. Tank vent and all related things. Assuming you checked things like the fuel line for being pinched somewhere between the handle and the carb etc.. and that the filter stays down in the gas when you have a partial tank full.....and I assume you checked the plug wire for grounding on the fins...that presents like a lean condition. AND you checked the seals with vacuum testing. Also assume you checked the pulse fitting and passage to be absolutely clear. With those assumptions, To me its got to be in the body of the carb, the low speed circuit somewhere and this is supported by your observations relative to the carb kits.. Or its ignition. Thats it. One or the other. Actually I have the separator in my carb, I guess that could be an issue but others seem to do fine without it.

Yep, same carb and ignition, and yeah, either replaced or checked all of the lines. I've blown the low speed circuit out like 10x, including both pressurized air and carb cleaner, from every direction/port/adjuster. I did grind that corner of the fin off, where it contacted the spark plug wire, but it wasn't rubbed through or anything. I'm to the point of trying to find a cheap carb just to test with, on ebay or something. I could swap the black coil in from my 371, but I'm pretty certain it isn't that, because it runs and idles fine as long as I don't let it just sit and idle for a while, and if I catch it as it starts to lean out, but before it dies, it'll bog like it's lean until it pulls some more fuel into the bowl, then it'll be fine again after a couple seconds of revving.

Though, I almost never let a saw low idle more than 20 seconds, anyway, at least a big/bucking saw, so I'm not sure that it's worth spending much money or time trying to fix, other than it bothering me not being "right." (we have similar real job backgrounds, so I know you know what I'm talking about)

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 15, 2016, 04:04:09 PM
Of course this saw has the $75 replacement carbs, and doesn't have any of the china copy $5-$10 carbs. I'd just buy a new one if they were $30-ish or something, but it's not worth $75 to me, to be able to idle this particular saw for more than 20 seconds without a blip. Of course, my 371's carb is different.

Just thinking about it, though, I wonder if even though I can suck and blow through the pulse line, if the hard line coming out of the case is bent at the bend a little farther than it should be or something, so it's just not quite flowing "enough" ??

Mike
Title: Re: 372XP X-Torq Modding
Post by: weimedog on December 16, 2016, 09:52:16 AM
Its details that are looked at time and again in situations like yours that end up being an issue, what about just setting the idle a little higher? Say 3000 vs 2800? The first one I did like yours on a used OEM top end wouldn't go lean at idle, but it would idle perfectly, then if you grabbed some throttle it would stall. Rich stall vs. fuel starvation. Suspected there was some pooling of fuel in that large intake with lower than designed air velocity to keep things mixed right. Spike60 had said he had better results with the divider in so I put it back in along with leaning the low speed a bit, and raised the idle with throttle stop a bit. Problem stopped. Not certain which of the three changes solved it! Didn't have time to evaluate it. And the second one I did for a friend just....ran, no goofy little issues. It was simply a no base gasket build and muffler mod build. Ran strong and is in one of the video's where I compared a variety of Husqvarna 70cc saws. SO every one is an individual.

The "Huztl" one I'm developing now didn't really present an idle issue that way. It tends to drift more to the lean side after a period of time as well but doesn't stall when idling. It has other issues. Solvable but its a different animal than the stockers. I've had to radically raise the exhaust and transfers on that one to fix its issues. Not an intuitive solution but brought the timing numbers back closer to stock..and it runs better than when I first stuck it together and the cylinder was as delivered. I have a theory why..:)
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 16, 2016, 10:49:45 AM
Yeah, I'll check that little pipe where it goes into the case, maybe give it a little squeeze with some pliers at 90-degrees to the bend, at the bend, to try and make the material at the bend a little more "round". There -is- supposed to be a bend in that brass tube where it comes out of the crankcase, right?

I had considered putting that separator back into the carb, but I broke it pulling it out (even with the choke out), and it doesn't look like it's available separately, looking at the IPL.

Yeah, the idle is around 2600. I'll raise it to 3k and see what I see on it. See if it idles for ever, there.

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 16, 2016, 11:00:25 AM
(https://forestryforum.com/gallery/albums/userpics/44237/IMG_20161216_105520.jpg)
Title: Re: 372XP X-Torq Modding
Post by: weimedog on December 16, 2016, 11:04:35 AM
yea..even 2800-2900..thats where mine are. that pulse? run something thru it to make certain its absolutely as clear as possible.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 16, 2016, 11:25:34 AM
Yeah, found a picture of it, cropped from a bench pic. That's the actual one, yeah. I'll run a pipe cleaner or something through it.

Thanks,
Mike
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 17, 2016, 09:38:18 PM
Pulse line is clean. Put about a tank and a half through it, today. Runs really well and idles fine, as long as you don't let it idle more than 10-20 seconds. I'm not going to mess with it any more, and if I happen to come across a cheap XT carb or another XT saw that I can swap carbs on to troubleshoot.

Mike
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on December 18, 2016, 07:30:36 AM
Quote from: barton174 on December 17, 2016, 09:38:18 PM
Pulse line is clean. Put about a tank and a half through it, today. Runs really well and idles fine, as long as you don't let it idle more than 10-20 seconds. I'm not going to mess with it any more, and if I happen to come across a cheap XT carb or another XT saw that I can swap carbs on to troubleshoot.

Mikeg

Did you set the idle higher as weimedog suggested?  I set my idle at 2800 +/- and I've never had the problem that you're experiencing.
Title: Re: 372XP X-Torq Modding
Post by: barton174 on December 18, 2016, 09:38:54 AM
Quote from: XP_Slinger on December 18, 2016, 07:30:36 AM
Quote from: barton174 on December 17, 2016, 09:38:18 PM
Pulse line is clean. Put about a tank and a half through it, today. Runs really well and idles fine, as long as you don't let it idle more than 10-20 seconds. I'm not going to mess with it any more, and if I happen to come across a cheap XT carb or another XT saw that I can swap carbs on to troubleshoot.

Mikeg

Did you set the idle higher as weimedog suggested?  I set my idle at 2800 +/- and I've never had the problem that you're experiencing.

Sorry, yeah, forgot to say that. The idle is 3100-3200. Still below the clutch engagement.

Mike
Title: Re: 372XP X-Torq Modding
Post by: Awesomesince72 on February 02, 2017, 10:11:10 AM
Any of you guys do any porting on the xt for other folks. Would like to do these mods to my 365 but don't have the time right now.
Thanks
Troy
Title: Re: 372XP X-Torq Modding
Post by: Awesomesince72 on February 04, 2017, 04:28:13 PM
Anybody got a pic of their 372xt muffler mod? Ice storm outside has me sitting in the shop with my porting tool in hand...I mean I was in the shop until power went out
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 04, 2017, 06:25:02 PM
I will put a tach on my ported saws tomorrow but 2800 is to high for me if your using the stock blue coil, if your using the black coil then that's fine , With the idle that high and blue coil the coil will be trying to advance the timing and you end up with the motor rpms going up and down at idle , that's the coil doing that
Title: Re: 372XP X-Torq Modding
Post by: weimedog on February 05, 2017, 09:39:08 PM
Quote from: ehp on February 04, 2017, 06:25:02 PM
I will put a tach on my ported saws tomorrow but 2800 is to high for me if your using the stock blue coil, if your using the black coil then that's fine , With the idle that high and blue coil the coil will be trying to advance the timing and you end up with the motor rpms going up and down at idle , that's the coil doing that

With mine anything less than 2700 it will idle nice but as soon as you give it throttle it stalls. It sits in the 2800 range plus or minus just fine. And responds to throttle. Just is what it is.
but it has a black coil.
Title: Re: 372XP X-Torq Modding
Post by: ehp on February 06, 2017, 09:43:08 PM
and that is why your up at 2700/2800 rpms , the blue coil has more advance built into it than the black coil so the blue coil will idle at a lower rpm
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on July 19, 2017, 06:39:01 PM
I'm digging this thread up cause I'm working on my 2166 currently. I have eliminated the strato intake and with that I started thinking. I can't see any negative to widening the intake some, it will open up to the strato cutouts on the piston but those will have fuel and air in them anyway. Only possibly is the strato closes at the transfer window about 2 degrees after the intake. Could you get spit back from that?
Anyone care to chat about that logic?
My intake is at 76 after cylinder adjustments
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on July 19, 2017, 06:40:21 PM
Wow, didn't realize that was my first post, I've been a member for a few years. Sorry I hadn't said hi.
Title: Re: 372XP X-Torq Modding
Post by: chet on July 19, 2017, 09:09:10 PM
Quote from: EvilRoySlade on July 19, 2017, 06:40:21 PM
Wow, didn't realize that was my first post, I've been a member for a few years. Sorry I hadn't said hi.

Roy, yer off da hook,  your registration date was January 31, 2017, 03:27:28 pm  :)   You musta been hanging around here alot longer than you thought before you registered. ;D
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on July 24, 2017, 05:05:18 AM
I didn't widen my intake for the reason you stated.  I see potential for spitback and loss of crank case compression.  The stratos will be open to the transfers and if the intake is widened to the point where the stratos are exposed the charge could come back through the intake before the transfers open.  At a minimum I think it would create a lazy charge due to lower crank case compression.  I'm no expert at all, hopefully someone with more experience chimes in.
Title: Re: 372XP X-Torq Modding
Post by: CJBrown on July 25, 2017, 06:45:41 PM
I don't have a 372XT but I have read this entire thread and it is very interesting. Lots of good info from all those involved. I am wondering if anyone has shaped the top edge of their piston to match the exh port roof shape for quicker opening of the exhaust port on the downstroke.
Title: Re: 372XP X-Torq Modding
Post by: ehp on July 25, 2017, 10:14:56 PM
I would not widen the intake port to that point, I always make sure the port is not that wide mainly cause you need cylinder wall metal for the piston skirt to run on , you open the intake port up to wide your intake skirt on the piston will get beat up pretty fast plus you will get spit back , now if the engine had reeds then you could open it up more but will would need a different piston with a wider intake skirt
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on July 27, 2017, 07:10:55 AM
Excellent point about skirt support Ed.  I hadn't even thought of that as I was more focused on how the intake, stratos and transfers are timed in relation to each other.  The XT piston skirt is very narrow compared to an OE piston because of the strato ports on it.  Reason #2 to leave the intake width alone.  In my mind one could make up for the lack of area by giving it a little more time, opening around 80* BTDC. 
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on July 31, 2017, 05:56:30 PM
Yes, thanks Ed for the reminder of skirt support. I'm just brainstorming on how to get the most area out of the three little ports. Ed, I remember you saying that you do a lot of work to the piston also. Maybe opening up the strato channels is an option to get more feed?
This is what I have started. I need to widen the transfer opening for some more area and cut more out of the passage to remove a tight squeeze area.


 (https://forestryforum.com/gallery/albums/userpics/44974/image~0.jpg?easyrotate_cache=1501537764) 

 (https://forestryforum.com/gallery/albums/userpics/44974/image.jpg?easyrotate_cache=1501537637)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 01, 2017, 07:17:53 AM
Your cylinder is looking good.  Brainstorming is the fun part of all of this in my opinion.  Having guys like Ed that are willing to guide us through our learning experience from theory to application is immeasurably valuable.  Can't wait to hear your saw run!
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 01, 2017, 07:24:09 AM
I've never heard of anyone shaping the piston to more closely match the curve of the exhaust port, although I'm sure there's someone that has tried it.  Makes perfect sense because the quicker you can open the exhaust the more efficient the port will be.  A common practice I've seen to achieve this is making the top of the exhaust port more flat.  But with this method comes risk, if the flat area is too wide you'll snag a ring.  This is where experimentation comes in but all my saws are ported now so I don't have any cylinders to play with...lol
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on August 01, 2017, 04:13:12 PM
So, as it stands now I've really only worked on transfers.
Totally stock:             After machining:
Tr 116                       121
Ex 99                        102
In 74                         76
Sq .030"                    .019"

Both with gasket.

Strato is gutted minus the divider in carb, I can see benefits in leaving it with learnings from the dirt bike carb world. I have not raised the roof of intake to bottom of piston at TDC yet but will. I've not yet decided to increase intake duration yet either, but maybe just enough to match strato ports for now.
Unfortunately I have not taken Ed's advice and CC'd the engine. I know how useful it is when traveling this road but...I really have no excuse other than it's not easy.
I've raised transfers to 114 and widened them towards the exhaust to the edge of the strato cut out on the piston. It seems a better visual than measurements. I am starting measurements of the transfers to decide if I want to go towards the intake, it's a bit more finesse.
No matter what I'll be widening the exhaust. As for raising it, I have chosen to take the approach of compression. I'm not sure it's right but if I understand correctly the relationship of transfers to exhaust dictates compression. I have no plan to go higher on transfers so now a goal of 180psi will dictate my exhaust height. Unless it's unreasonable. I did remove .020" from the squish. Worst case I can remove some material from combustion for more volume up top.

Any insight is welcome as I travel this new road.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 02, 2017, 07:09:27 AM
When I raised my exhaust 3* I only lost 5psi of compression if I recall correctly.  My squish is at .024 which gave me 180psi before raising the exhaust.  Being that you're at .019 I don't think you'll have any problems achieveing your goal of 180psi.  I'd be willing to bet that you'll be at 190 or maybe even a touch more with your exhaust as low as it is now.  If you have the room in compression to raise the exhaust I definitely would.  When I built my Saw raising the exhaust really woke the up.  While raising and widening ports, don't forget about your ring locator pins.  You don't want ring ends dropping into a port as it will likey snag. 
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on August 02, 2017, 12:58:16 PM
Thanks, I have avoided anything near ring ends. I'm easily clear of rings at the top of intake while getting full open at TDC. I didn't touch the strato ports because they are near something at just about every position.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 02, 2017, 02:30:33 PM
I assumed you were aware of being cautious of the ring ends, never hurts to bring it up.  Especially with other folks reading along.  When do you think you'll be running your saw?
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on August 02, 2017, 03:29:58 PM
I understand completely about the ring comment, it never hurts to bring things like that up.
Next steps is bevel the ports, then drop the cylinder on with rings to check compression. I'm only doing this to learn. I'll be getting a baseline after cylinder machining and raising/widening the transfers. After that I'll pull again to widen and move exhaust to around 100, then check PSI again. If needed I'll raise exhaust some more but not beyond 98 for now. I'd be happier removing some combustion chamber to reduce compression at that point. Maybe even raise transfers another degree.
Title: Re: 372XP X-Torq Modding
Post by: CJBrown on August 02, 2017, 09:34:41 PM
What kind of rotary tools are you guys using to do your own porting?
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 03, 2017, 08:09:18 AM
I used a dremel with long shank burrs.  Not ideal but it worked well enough.  Saws such as the XT with removable transfer covers make it pretty easy to get by with a dremel. 
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on August 04, 2017, 01:14:46 PM
I have a Fordom knockoff from HF with some Chinese hand pieces. The hand pieces are quite well built for the price.

I have a question about grinding on the piston. I'm hoping @ehp will help out because he mentioned working it over pretty good. I'm touching up any areas on the piston just to drop any bit of weight I can. I know the intake skirt takes majority of side force abuses from the rod, so I wondered about removing some skirt from the exhaust side. I have 1/2" before freeport occurs, I would think I could remove 1/4" safely. In my opinion removing weight (smartly) from the piston will help lower end lifespan and possibly reduce wear on the intake skirt. It's heavy and has got to be stressful and energy sucking to stop and start.

Anyone have experience with this idea. I know it will change front to back balance. I've not seen much wear on the bottom of any saw exhaust skirt. The stress on intake seems to occur both up stroke and down. Up is Rod driving towards the exhaust which rocks the piston that direction forcing the intake skirt against the wall. Then down is the piston driving Rod down which the angle is using the intake wall as a sliding surface. Less piston weight means less force to change direction, less force= easier rotational momentum.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 04, 2017, 06:43:54 PM
I think removing that much material from the exhaust skirt could cause it to get too hot.  Less metal to absorb heat causing premature aluminum transfer to the cylinder wall.  Just a hypothesis, not based on any experience on this subject.  Very interesting thought.  You're right about the XT piston being heavy.  I actually weighed one and it came in 10gr heavier than a 75cc XPW piston.  Not a huge difference, but the fact that it is heavier than the big bore piston says a lot.
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on August 04, 2017, 07:02:46 PM
I started thinking about other pistons I've seen that aren't symmetrical, like the ms261, 562. I'm sure there are others. I wish I had piston and cylinder of those in my hands to investigate. Well I do have a brand new 562 but don't feel like pulling the cylinder, yet...
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 04, 2017, 08:34:02 PM
Got a feeling you're gonna be investigating that 562 sooner rather than later...lol. 
I've never seen a piston that wasn't symmetrical or very close to it.  As you said, you could shed some serious weight if it's a viable option to shave the exhaust skirt.
Title: Re: 372XP X-Torq Modding
Post by: ehp on August 05, 2017, 09:22:09 PM
Lots of guys cut the skirts on pistons , I am not one of those type of people . I never cut skirts ever, seen way to many pistons crack or break from that, I lighten piston doing the casting flaws, and work the inside over pretty good . Also guys you have to remember a port can only pass as much air/fuel at the smallest area of the port, I see lots of guys put huge transfer ports in the cylinder but channel of the port is no where even  close to being able to pass that amount of charge so measure what your grinding , In a lot of times doing those huge transfers but not a lot else hurts the power of the saw , Everything has to work together , modding the transfer ports hard but not the ext port does not work either
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on August 06, 2017, 12:25:13 PM
Ed, thank you for the insight. I'll leave the skirt alone. I have been working over the piston pretty good elsewhere though, inside and out. I have heard you say ports can only flow the smallest area before and I try to approach grinding like that. I've also heard from many people that these single transfers need to be opened a lot.

I've measured my ports as best I know how.
Transfer bottom   188mm^2
Transfer tunnel at turn   159mm^2
Transfer opening to cylinder minus the top edge of piston that is in the way at BDC   178mm^2

Intake still at 76 degrees   275mm^2
Strato ports together untouched   137mm^2

Just looking at those I see I need to open the tunnel more. The intake I am just guessing at but I'm sure with knowing crankcase volume and compression duration it can be figured out. However I have never done volume and barely understand how. From a post long ago Ed said to block intake and exhaust ports and fill the whole engine up to the spark plug threads with ATF I thought. To me, anything non foaming with a surfactant would work. Measure that volume of liquid, subtract the given engine CC and you have crankcase CC. Is that correct?  Then you would use a formula that I do not know to determine your intake needed, transfer volume, blowdown and compression.

So for now, I need to go find T/A reading.  Then maybe I can determine if I at least have close numbers. Or I set the exhaust and run it, see what it does.


Title: Re: 372XP X-Torq Modding
Post by: ehp on August 07, 2017, 09:40:07 PM
No, you put engine at TDC and it has to be TDC perfect, fill combustion chamber to second thread on sparkplug hole , measure how much volume of oil you used , next role piston down to BDC fill to second thread on sparkplug hole , measure oil volume used , now you got to have the ports closed off but you already knew this and you would already know the cc volume of the engine . I have a computer program that I put the number in and it can tell me pretty much everything I need  now I can make changes to my ports like transfers that will add cc volume to the crankcase and see how that affects the engine , I also have a engine dyno on computer that I can take a engine numbers and port and the dyno will tell me if they work or if the port numbers are wrong mainly thou on if your over porting a port the computer will tell you that will not work. But I honestly cannot remember the last time I used any of that stuff , Had so many different motors apart I pretty much just look and can tell what I want to do
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 08, 2017, 05:40:23 AM
Interesting stuff.  I've never measured Case volume, seems like a more precise way to determine what changes should be made to ports. 
Title: Re: 372XP X-Torq Modding
Post by: ehp on August 08, 2017, 05:47:15 PM
crankcase volume plays a huge roll in how a motor runs and mainly torque , you can make top end horsepower playing with making the volume larger but at some point it will become a very top couple hundred rpms will be any good to you. But on average most chainsaw motors are to tight and can use a larger crankcase volume and they will make more horsepower but the down side is the engine will also require more fuel and that amount of fuel depends on the amount you increase the cc volume of the crankcase and also with more power you will produce more engine heat which is not a good thing
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 09, 2017, 06:33:37 AM
Yes sir.  It's that delicate balance that we're all looking to achieve.  It's the difference between a DIY woods port and a pro such as yourself.  I really enjoy learning about this stuff. 
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on August 09, 2017, 08:10:17 AM
Which is were the whole BMEP comes into play correct?  It would be fun to see the simulations on the software to help understand what affects what. Watch what happens when fat lazy transfers are ground and such.
Title: Re: 372XP X-Torq Modding
Post by: CJBrown on August 09, 2017, 09:08:51 AM
If a larger crankcase volume is desirable when trying to produce more HP, what role do crank stuffers play in some of the production saws? Is it to keep the charge above the spinning crank and out of the bottom of the crankcase? Reduce bottom end turbulence? And how do they affect bottom end lubrication?
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on August 09, 2017, 09:54:01 AM
The way I understand crank stuffers is they increase charge velocity and pressure.  Which in turn gives the Saw more torque at higher rpm.  I think...
Title: Re: 372XP X-Torq Modding
Post by: ehp on August 09, 2017, 06:06:22 PM
Bmep is a ratio that can help BUT you still have to use common sense cause you can design a engine that has a super high Bmep number that looks on paper or computer screen to be super but in real world terms the engine could never run at that Bmep ratio . Just like most computer software you still need to think , same as building 2 stroke pipes . You need to tell the program what you want to do,
Title: Re: 372XP X-Torq Modding
Post by: CJBrown on August 09, 2017, 06:29:50 PM
BMEP - I had to look that one up.
Title: Re: 372XP X-Torq Modding
Post by: SierraMtns on December 28, 2017, 12:11:22 AM
Great thread.  I am currently porting my 365 x-torq.  This is the first time I have ported a saw.  I am a little nervous so I am and going slow. 

I am hoping to post pictures soon. 
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on December 28, 2017, 10:25:37 AM
Quote from: SierraMtns on December 28, 2017, 12:11:22 AM
Great thread.  I am currently porting my 365 x-torq.  This is the first time I have ported a saw.  I am a little nervous so I am and going slow. 

I am hoping to post pictures soon.
Looking forward to it.  I like how this thread keeps on rolling as more folks chime in with what they're doing. 
Title: Re: 372XP X-Torq Modding
Post by: SierraMtns on December 28, 2017, 08:47:43 PM
Quote from: XP_Slinger on December 28, 2017, 10:25:37 AM
Quote from: SierraMtns on December 28, 2017, 12:11:22 AM
Great thread.  I am currently porting my 365 x-torq.  This is the first time I have ported a saw.  I am a little nervous so I am and going slow. 

I am hoping to post pictures soon.
Looking forward to it.  I like how this thread keeps on rolling as more folks chime in with what they're doing.

Yeah I was thinking about starting my own thread for this build but I think its cooler to join your thread and keep it going with the x-torq mods. 

I primarily cut soft wood (Pine, Doug Fir, and Cedar) out here.  On average the trees are 30" on the stump.   

The stock squish is 0.43" and compression is 155 psi.  This saw has 1.5 hours on it.  I was getting 9,500-9,800 rpm cutting a Digger Pine log.  The log was 29" and I am running a 32" bar with skip tooth and 50 ga chain.  I had to feather the saw in the cut because the chain would stop if I was really pulling on it.  My rakers might be a little low. 

I swung by our local machine shop today to see about cutting the base and sadly they don't have a jig to do that.  So it looks like I will either need to send it off or just do a base gasket delete. 


Will be posting pictures soon. 






Title: Re: 372XP X-Torq Modding
Post by: SierraMtns on December 30, 2017, 11:40:38 PM
Ok guys here is where I am at.  I marked out the areas I will be grinding.  I will start on the lower transfers to get some practice.  I put the base gasket on and will port match the gasket to the transfers. 

What do you guys think?  See anything you would be concerned with?   I don't want to grind off to much. 

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0890.JPG?easyrotate_cache=1514694900)

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0891.JPG?easyrotate_cache=1514695052)

Title: Re: 372XP X-Torq Modding
Post by: SierraMtns on January 01, 2018, 09:13:30 PM
I did some porting today to the intake and lower transfers.  I still need to get some stones to polish the ports. 

What tools do you guys use to polish the ports?  How smooth do they need to be?   

Thanks

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0908.JPG?easyrotate_cache=1514858948)

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0900.JPG?easyrotate_cache=1514858946)

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0897.JPG?easyrotate_cache=1514858945)
Title: Re: 372XP X-Torq Modding
Post by: SierraMtns on January 01, 2018, 09:16:56 PM

I am not sure if you guys can see the upper ports but I tried to make them come together and not have the air hit a wall. 

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0895~0.JPG?easyrotate_cache=1514859342)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 03, 2018, 01:02:11 PM
Hard to tell in the pics but I think you need to take more material out of the lowers.  You've funneled them slightly but didn't really widen the port overall.
Title: Re: 372XP X-Torq Modding
Post by: SierraMtns on January 04, 2018, 12:36:41 AM
Yeah I was thinking I needed to widen the lower transfers more too.  I was censored with the screws holding the transfer caps.  I marked out the area where I will widen them. 

Also I marked out the exhaust port to widen and transfers. 

What I am stuck on now is the transfers.  I can not figure out a way to mark them out 0.30 lower.  Do you guys have any tricks? 

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0927.JPG?easyrotate_cache=1515044044)

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0937.JPG?easyrotate_cache=1515044044)
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 04, 2018, 08:05:31 AM
You're right to be concerned about the cap screws but you've still got plenty of room.  Slow and steady and you'll be fine.  The following video is how I find my height based on desired degree of opening.  Courtesy of mastermind.
https://youtu.be/h9dVpnEmzRY
Title: Re: 372XP X-Torq Modding
Post by: SierraMtns on January 05, 2018, 10:36:18 PM

I did more grinding today and polished the lower transfers and intake.  I went down to 180 grit and then a rubber polisher.  How smooth do you guys make? 

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0974.JPG?easyrotate_cache=1515209565)

(https://forestryforum.com/gallery/albums/userpics/48014/IMG_0976.JPG?easyrotate_cache=1515209566)

Man these lower transfers are hard to photograph. 

Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on January 06, 2018, 08:41:14 AM
You actually want the intake and transfer passages to be textured not polished.  Texture creates surface turbulence that prevents fuel from falling out of suspension and sticking to the port wall.  Think of it like when you drive through thick fog and the moisture sticks to your windshield.  Same thing will happen with atomized fuel in your ports and cause fuel to puddle.   Someone chime in if I'm off on this but I understand it to be pretty standard practice.
Title: Re: 372XP X-Torq Modding
Post by: NCFarmboy on January 07, 2018, 09:17:13 PM
I use 80 grit - 120 grit for intake.  Whichever I have on hand.
Shep
Title: Re: 372XP X-Torq Modding
Post by: EvilRoySlade on February 10, 2018, 08:22:13 AM
I can’t really tell but it looks like you didn’t open your intake window yet. You want to grind the upper part of the intake all the way up to the bottom of your piston skirt when at TDC. Always be sure to check where your ring is at BDC though before grinding. You’ll be fine in this case but no sense ruining a cylinder just cause someone said it’s okay.

Don’t go any wider though, it’s been mentioned earlier but it should be brought up again.
Title: Re: 372XP X-Torq Modding
Post by: Rx7man on August 12, 2018, 02:03:53 PM
Wow, that was a marathon read to get through 24 pages, but I enjoyed it a lot.. I got a 372xt and the P&C aren't in that great shape so since I can't leave well enough alone, I'll fiddle with it!.. This is the only place I've seen a discussion that says you can get significant power gains from an XT saw, which makes me happy.

I am no pro at porting, but I've done a dozen or so saws of my own, I own half a dozen L65's, and they're a great learning platform since they're a pretty poor performer from the factory.  On my wildest one, I was going for top end power, so I went aggressive on the intake and exhaust durations, about 170* of exhaust and because of more machining of the base after porting the intake I ended up with about 180* of intake.. It sounded great on the bench free revving but it was an absolute dog in the wood, it was untunable because of intake reversion (when the intake charge reverses, the carb doesn't care which direction the air is flowing, so it adds fuel once the first time through, once on the reversion, and then once more as it draws it back in).. so at low RPM it was pig rich to be right at high RPM.

I came to the conclusion that my best gains would come from transfer port work since these saws had tiny transfers.. I had already done a little bit of work to them, but a lot more could be done.  They were a bottom fed closed transfer design and I converted them to a piston and bottom fed design, much like a 394 or Jred 930.. I windowed the piston and cut massive amounts from the cylinder wall.. I was limited in what I could do to the upper transfers because I don't have a right angle grinder small enough so I notched the piston to get more open time.  I was actually looking for more case volume because I wanted to lower the harmonic frequency in the case to reduce the reversion.. Basically a slower moving charge over a longer period of time because of the greater case volume.  
By the time I was finished, it felt like a whole new saw, stall RPM went up considerably from stock, so more low end torque, and in-the-cut RPM went up a lot, with more power everywhere.. It was very rewarding!

Now on the the XT... I haven't really studied it that much yet, but there are some things I'm surprised haven't been brought up yet.. In strato form, the bearings should be getting much better lubrication since the mix is quite rich to the bottom end, more important the less oil mix you run (like many of you, I like 32:1 for a hard working saw)
I haven't had the piston/cylinder in my hand very much to examine how the strato ports work, but since they go through the piston, that's a little bit of cooling to be had, but I haven't seen any one doing any smoothing/polishing on the piston cutouts, and it may be possible to change some of the timing there as well, though it looks hard to measure.  

Anyhow, I loved this thread (including the squarebody talk, I have '92, 93, and 94 dodge diesels, and have less fond memories of the '80 Blazer (I lived in it when I was too broke to afford rent))

Look forward to tearing my saw apart again when new rings get here and doing some work to it.. I think I'll try leaving it as a strato from the choke onward, and removing the divider in intake elbow, at least for now.. I want to see what I can get out of it without making it too thirsty.  Thanks for all the info and the great read!
Title: Re: 372XP X-Torq Modding
Post by: ehp on August 15, 2018, 01:01:20 PM
I still say one of the best motors out there, I got XT's that I ported out in the field that are still going being used by loggers and are 5 or 6 years old . Myself I leave the stock limited coil in saw but advance the flywheel, this stops the saw from over revving and hurting the crank/rod bearings when limbing and stuff . I gut everything but lots of guys donot . One of my own saws that I cut with and setup up will start and run the easiest of any saws you can run . Yep per hour I burn more gas but I cut a lot more wood per hour as well . Will I be rushing out to buy the new 572 , not to likely but that again is my idea
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on November 21, 2018, 03:17:11 PM
I'll be tearing my 372 apart this winter to inspect the plastic caged bearings.  I've got a good amount of run time on it now with the unlimited coil.  I'm curious to see how the bearing retainers have held up to the higher rpm.
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on November 21, 2018, 03:19:37 PM
Wish I would've known you were at Boonville Ed, I'm only 45 minutes from there and it would've been great to meet you and shake your hand. 
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 24, 2018, 01:42:56 PM
Ya my wife and I went and it was a good show . I have had zero crank problems or bearing problems but I do run 40-1 using what I think is oil . I will not be getting a new 572 now I donot think . I like the little light hotrod saws
Title: Re: 372XP X-Torq Modding
Post by: XP_Slinger on November 27, 2018, 04:20:27 PM
Yeah I hear you on that.  I haven't had any bearing issues with my saws either.  The new 572 intrigues me because it's new, but I won't be trading in my trusty 372 to get one.
Title: Re: 372XP X-Torq Modding
Post by: MG2186 on November 27, 2018, 04:29:12 PM
Quote from: ehp on November 24, 2018, 01:42:56 PM
Ya my wife and I went and it was a good show . I have had zero crank problems or bearing problems but I do run 40-1 using what I think is oil . I will not be getting a new 572 now I donot think . I like the little light hotrod saws
Ed do you still port saws or just your own? 
Title: Re: 372XP X-Torq Modding
Post by: ehp on November 27, 2018, 07:36:39 PM
mainly my own or a few friends close to me up here
Title: Re: 372XP X-Torq Modding
Post by: MG2186 on November 28, 2018, 11:01:20 AM
Wow, just finished the whole thread. Very good read and super informative. I have a whole new respect for XT saws and will definitely look at them in a different respect. Ed's knowledge of these motors seems to be unmatched by anyone I've come across. Again good read and great job by all 
Title: Re: 372XP X-Torq Modding
Post by: barton174 on January 19, 2019, 07:04:56 PM
Well, I finally figured out the issue with leaning out and dying at idle after 10-15s! Looking at the IPL, with the machined bottom carb cover, you use only one of the gaskets on the top side of the diaphragm, but I have the stamped cover, and I guess you're supposed to use a gasket on top and bottom of the diaphragm, with said stamped cover. Added the second gasket and boom, idles great!

Mike
Title: Re: 372XP X-Torq Modding
Post by: Wonka13 on September 07, 2021, 09:59:31 PM
Well, I think this thread has idled(😆) long enough!😁. Getting ready to dig into my 2021 372xt. I've watched all the YT videos you guys have put out, and many more...I'd say I've got a few hundred hours of research in on the 372/385/390....but, alas, I'm still a new dummy to saw modding. My plan, to start, is to cut out the strato-stuff on the AF holder & intake boot, in addition to doing a base gasket delete (current squish is ~ .045"). I'll see how it runs after that prior to going dremel mining on the cylinder...though I may reprofile at least the intake into more of a knife-edge while I'm fiddling...heck, I'll already have the dremel out and intake boot off after all😉😆. Any long-term feedback from you guys that have been running these saws, in various modified forms, for the last 5 or so years?  Lessons learned, improvements made?  Thank you for your willingness to share your hard earned knowledge!