Modify Saw Muffler .... is It Worth It or Not and How To Do It ? ? ?

[Cut4fun]

Yep Kevin the 266 I was referring to you was the one I sent up to you with the clean looking top end.  Glad to see someone get use out of it.
I got 2 more 372 tore down to cranks right now with a like new looking Mac 805 I dont want no part of working on  and a Partner 550 tore down that I might end up with a 7000 plus topend on in the future.

[Al_Smith]

Gordon Jennings would be in hackers heaven here....Oh..By The Way:
http://www.datafan.com/TunersHandbook/2-strokefiltered.html

I downloaded it a long time ago and printed it out .Between that,Mac Dizzy,several RC forums,motorcycle forums and several chainsaw related sites I just keep plugging along .All that plus a few little "hints " I get along the way .

Put it on the "wheel " map the ports, scratch your head for a week thinking it over and change your mind half dozen times then get with it .Put it back together ,run it,tear it back down and do some more .Stop before you wear the bolts out . :D

[Sawz all]

I appreciate the candor Saws all...and thanks for the tips & numbers. And it looks as if this thread has now attracted the attention of some real knowledge.

No problem weimedog. But who am I? Chop liver?...lol..., before the "real knowledge"...lol...

Kevin

[weimedog]

I appreciate the candor Saws all...and thanks for the tips & numbers. And it looks as if this thread has now attracted the attention of some real knowledge.

No problem weimedog. But who am I? Chop liver?...lol..., before the "real knowledge"...lol...

Kevin

I doubt it! You are way further along the curve than I am, that I do know. I have seen some of the work from "That other guy" you are referring and its pretty impressive, and therefore tangible. I don't know either one of you guys but I am quite pleased you folks decided to drop in and leave some knowledge behind....

BTW my guess is you probably left that gasket out to help with the torque with that intake number. (Understand I'm basically clueless relative to port timing..just a guess) I would have loved to see how many R's you got out of that thing no load!

[wannabeonetoo]

Looks like the RS crowd has dropped in !!!!!!!!!!   :D

Steve

[weimedog]

For now. They are in a different league playing a more serious game relative to performance. I can't talk for most, but many are more interested in reliability and / or like in my case just getting an eclectic group of hobby saws to run is a win.  Also the focus here is the forestry side of things. One of the reason's I'm here as there is a lot of knowledge on issues important to me as a landowner & farmer with wood lots. Saw's are tools first and a hobby for me second. BUT the "racesaw" concept sounds like fun for an old clutch head like me!

[Sawz all]

weimedog,
Believe it or not I don't own a tach, I do everything by ear. Sometimes I take certain saws I do over to a friends who has a tach and figure out what the revs are.

Rule of thumb; the higher you take your exhaust the more revs but you loose torque, you have to find a nice balance.
Port shapes and angles all have things to do with the final result. As a porter is porting he or she must be thinking ahead as to down stream effects.

There is a lot to learn and I can tell you I learn something new every time. Anybody who tells you they know everything is full of chit.

Kevin

[weimedog]

 8) :P :D

Again I appreciate the info & insight! Good stuff and I couldn't agree more with your analysis...I'm all ears for insight.

[Sawz all]

 I have seen some of the work from "That other guy" you are referring and its pretty impressive, and therefore tangible. I don't know either one of you guys but I am quite pleased you folks decided to drop in and leave some knowledge behind....

[/quote]

That "other guy" is one of my mentors....

Kevin

[weimedog]

I have seen some of the work from "That other guy" you are referring and its pretty impressive, and therefore tangible. I don't know either one of you guys but I am quite pleased you folks decided to drop in and leave some knowledge behind....

That "other guy" is one of my mentors....

Kevin
[/quote]

Then you are one lucky SOB when it comes to getting saw building insight! (And there for like guilt by association fall under the knowledge umbrella)... There is another guy from the Ontario area I wish would drop in from time to time as well...there are some really good folks out there.

[Al_Smith]

There is a lot to learn and I can tell you I learn something new every time. Anybody who tells you they know everything is full of chit.

Kevin

Truer words were never spoken .

[ScottWojo]

Welcome ScottWojo

Tell us about the tips and materials.
Thanks.

Sorry about the delay.  Been busy and away from the net. 

Not sure what kind of tips you need.  I build my mufflers with stainless pipes,  and stainless screen.  If your going to make a cooler saw,  it should look cool too.

I just meant,  if you have a hard time finding stuff for your saw,  or if you need help figuring out what size pipe to use,  or if you even want to use a pipe.  Or if you just don't want to even do it your self.  I know plenty of muffler makers and can steer you into the right place. ;D

[Al_Smith]

 :D Oh pshaw ,a rusty muffler works as good as stainless one .Besides that steel is a sight easier to work with than stainless which everybody thinks is the wonder metal of which it is not .

I've seen stainless exhaust sytems on custom cars that will turn as blue as any other metal so what good is it ? I mean after a while the stuff looks like anodized aluminum , how cool is that ?---but it doesn't rust in the true sense of the word for what that's worth . :

[weimedog]

Part of the fun is the "chicken chit to chicken soup" concept of taking an old saw and bringing it back to life. There is little of no risk in hacking up a dented and rusty old can of an exhaust and its fairly low tech & easy to do rather effective mods. AND its yours..all elbow grease investment. Many times things like that old Husqvarna 61 or Jonsred 920 were one step away from the scrap pile...they simply aren't worth putting much into from a cost perspective as even all cleaned up they are $150-$200 dollar saws! Having said that... there are the folks who would like to "bling" out new saws and have a performance benefit as well...different groups of folks, both will look to difference places for satisfaction and therefor are reasons and room for both. And why not? Think of all the stuff people put on cars, motorcycles, and trucks etc to make them look and run better. Why not here in this motorsport?

[Al_Smith]

You don't have to have a degree in mechanical engineering nor a degree in It tech tech to rework a saw engine  .

What you need is the tenacity of a wolverine to carry it though .If it works ,fine ,if not so what ,at least you tried .

[weimedog]

You don't have to have a degree in mechanical engineering nor a degree in It tech tech to rework a saw engine  .

What you need is the tenacity of a wolverine to carry it though .If it works ,fine ,if not so what ,at least you tried .

Funny you say that! That's so true....and what you said about "Yankee ingenuity" with a die grinder a few postings back. And if you think about it most of the major innovations of the last 100 years happened without degree's.

[Al_Smith]

Oh yes the famous "McCoy oiler "used on steam engines was the product of a pharimistist ( can't spell ) .Never the less the real McCoy .

[Spike60]

I'm generally part of that 99.9%. However, in my case, I was having trouble with my 2152 overheating. It would run just fine for a full day of felling (generally time to cool off between cuts, or lighter loads when limbing). When bucking hardwood for firewood, it would run OK for a couple hours, then stall and have trouble starting again unless I let it cool down first.


John Mc

What causes this is indeed the cat muffler. In sustained use, the heat from the cat will gradually increase the crankcase temp to the point where the saw will simply not run right due to fuel atomization issues. Take it to a shop, and gee, there's nothing wrong with it. Back to the wood pile and the problem returns. I stopped selling 359's and 2159's due to this problem, and this is why it's so important to get a non-cat 346 when you buy one.

Back to the main topic; muff mods do make more power on most saws in my experience. Some will show more dramatic gains than others. A 372 wakes up pretty nice. Most of the larger Stihls come with a very small outlet hole, and some nice gains can be had by enlarging them.

[Al_Smith]

Thanks to the EPA the saw performance has gotten worse over the years .It's not the fault of the manufacturers ,they have no other choice but to comply with the governmental edicts .

I had to laugh  few years back when one of the guys ran a stock either 181 or 281 Husky  in the 0-100 cc class at one of our GTG's .It was up against souped up 066's ,2100 Huskeys and the like and although it didn't win it did exceptionaly well being 5 cubic inchs .

One of the other participants who fancies himself a guru of saws insisted it was a race engine but declined to take a look through the exhaust to verify that as fact . I was rolling on the ground laughing because I for one knew how well that praticular saw model ran  in stock form . :D

[Sawz all]

I'm generally part of that 99.9%. However, in my case, I was having trouble with my 2152 overheating. It would run just fine for a full day of felling (generally time to cool off between cuts, or lighter loads when limbing). When bucking hardwood for firewood, it would run OK for a couple hours, then stall and have trouble starting again unless I let it cool down first.


John Mc

What causes this is indeed the cat muffler. In sustained use, the heat from the cat will gradually increase the crankcase temp to the point where the saw will simply not run right due to fuel atomization issues. Take it to a shop, and gee, there's nothing wrong with it. Back to the wood pile and the problem returns. I stopped selling 359's and 2159's due to this problem, and this is why it's so important to get a non-cat 346 when you buy one.

Very good post! I never really thought of it that way, thanks! I know That 359 I'm doing right now had the worst cat in it I've ever seen!

I had a husky 575 that came through with a problem I could not fully duplicate.....once it was running for a while (good and hot) and the guy shut it off he would have a hell of a time trying to get it started.

Kevin

[ScottWojo]

Al,

I know how you feel about stainless.  Sure gun bluing or some other ano looking stuff would be cool too.

And probably just about anything else would be too.   I just like the look of the stainless,  and once the welds are blended in,  they really are nice.   And once it turns color its not a big deal to make it look new again.

And you really do not need to be an engineer to do much of the simple things.  And it doesn't take long for knowledge to replicate and improve itself.    Just have to do it and keep doing it.

[Al_Smith]

Well the stuff is what it is .I'm not opposed to it. Fact a lot of the  bells and whistles on a couple of Harley choppers I had were stainless .You can buff it to look like chrome if you desire .

A saw though isn't a hot rod Harley  but you know different strokes for different folks .