Well, this'll probably start a fight...but I don't care.
I recently bought a Tech Tach 20K. BEST PURCHASE I EVER MADE! This takes MOST of the guess work out of tuning. Notice I didn't say ALL?
That's because you STILL need to know how the carb works, and what to look/listen for in the saw. But, it's a great place to start, and an incredibly good reference tool.
I used to tune exclusively by ear. But, now I know I was not always on the money.
On my 372XP, it was WAY too lean from the factory. I had tuned ot by ear long ago. Then I bought the tach. It was STILL a good ways off. Oh, it 4-stroked fine, but the RPM were still higher than you would want.
After I tuned the HI and LO needles with the tach as specified in the workshop manual, I still did not like the way it ran. So, I did a little more experimenting.
With the max RPM at 13,500 (spec), the saw would not rev "crisply" to that speed. It labored a bit between 12,000 & 13,500. Also, it would not "clean up" exactly as I wanted in the wood. Oh, it was fine in a 24" white oak, but would still 4-stroke a little in smaller (12") logs/limbs.
So, I went back lean just a fuzz (maybe 1/16 turn?). Now, it cleans up much quicker, even in smaller stuff. On limbs, it toggles back & forth between 2-stroking & 4-stroking. Just a little pressure cleans it right up.
Checking with the tach, it revs up more crisply, and peaks at about 13,800-14,000 RPM. In the big oak, it easily pulls at about 10,200 under chain load only. Leaning on it drops it down to about 9,600-9,800. It takes a LOT of pressure to get it down below 9,000. And, this is with a VERY aggressive chain setup (but, that's another argument in the making!). So, now I know where this particular saw likes to run, and can put it back to that number quite easily.
Without the tach, my settings were still way off. The newer saws are just harder for me to "hear" than the older ones. But, once the tach was used to get into the correct zip code, the sounds are easier to judge.
So, my routine from now on is to use BOTH the tach and the ear to tune a saw. For those of you who only trust one or the other, try it. You might like it.
Keep in mind that, even though a saw is 4-stroking out of the wood, it still may be hurting itself. I make bearings for a living, and I can tell you that every bearing and seal in the world has a maximum RPM. If your saw sounds fine, bit is turning 2,500 RPM faster than the design spec, rest assured you are hurting the bearings and seals. Also, the piston speed may be higher than tolerable.
On the other hand, as I saw on mine, going strictly by the tach may not be 100% perfect either. Oh, I know I was not spinning mine too fast, but it would have had more carbon build-up had I left it set to the tach-only setting.
So, with a combination of a tachometer and a calibrated ear, I feel like I now have my saw set the best it has ever been. And, I could not have got it there without both.
Let the fight begin!
Quotethis'll probably start a fight...but I don't care.
I wish that you would care... makes for a much better Forum that way.
DCWeasel...... what you say makes perfect sense to me.
DCWeasel, well written and informative post. But, you're opening and ending statements were totally not necessary as it implies you are looking for a fight. If that is the case , you are on the wrong forum.
No matter what the tach says if you have them 4 stroking out of the cut and cleaning up with a little pressure you'll have them tuned good. Back some years ago nobody tuned with a tach and there weren't many burnt up saws . Steve
Fatcougar made a good point in the other thread . Modern saws will quit slobbering and two stroke under load at about 10,500 or 11,000 RPM. And, they will actually work fine that way, particularly on synthetic oil that doesn't carbon up so much.
But, that leaves you a window of 2,000 or 3,000 RPM to reach factory specified max no load RPM. Anywhere in that range will work.
I suspect saws tuned by ear are all over the place in that range.
Quote from: Chet on December 31, 2013, 12:54:39 PM
DCWeasel, well written and informative post. But, you're opening and ending statements were totally not necessary as it implies you are looking for a fight. If that is the case , you are on the wrong forum.
I think you missed my point. I hesitated to start this post because I figured there would be a bunch of bickering between the ear guys & the tach guys. But, I risked it anyway as I felt the information might be helpful.
Quote from: Fatcougar on December 31, 2013, 12:44:13 PM
DCWeasel...... what you say makes perfect sense to me.
Thank you, sir!
DCWeasel, I think you missed my point. The only problem with you're post was the begining and ending statements.
Never had a tach to use, I guess I tune mechanically. I adjust so that the saw idles without the chain moving, so the saw doesn't bog down in the cut, and when the trigger is pressed the saw accelerates without stumbling or hesitating, and try to leave the H a leeetle bit rich.
I read about 2 and 4 stroking, and have listened to Madsens WAV files until my ears are about to fall off, and I can not tell the difference! It all sounds the same. Maybe it has something to do with tinnitus, I have ringing in my ears all the time.
My saws may not be tuned for 'optimum' performance, but at least I've not burned one up in 40 years. :)
Loren
Quote from: ZeroJunk on December 31, 2013, 01:06:22 PM
Fatcougar made a good point in the other thread . Modern saws will quit slobbering and two stroke under load at about 10,500 or 11,000 RPM. And, they will actually work fine that way, particularly on synthetic oil that doesn't carbon up so much.
But, that leaves you a window of 2,000 or 3,000 RPM to reach factory specified max no load RPM. Anywhere in that range will work.
I suspect saws tuned by ear are all over the place in that range.
Interesting and useful info. Thanks!
Quote from: ZeroJunk on December 31, 2013, 01:06:22 PM
Fatcougar made a good point in the other thread . Modern saws will quit slobbering and two stroke under load at about 10,500 or 11,000 RPM. And, they will actually work fine that way, particularly on synthetic oil that doesn't carbon up so much.
But, that leaves you a window of 2,000 or 3,000 RPM to reach factory specified max no load RPM. Anywhere in that range will work.
I suspect saws tuned by ear are all over the place in that range.
Brown's Summit?
Ever make it over to Jordan Lake or Falls Lake?
Quote from: Chet on December 31, 2013, 01:44:36 PM
DCWeasel, I think you missed my point. The only problem with you're post was the begining and ending statements.
Well, let me apologize for the opening & closing comments then.
In the future, I'll try to do better.
Really appreciate your post. I used to be an ear only type but got a tach a while back and it really helps much like you said. Neither is better or worse but together create better results.
Thanks
Quote from: pine on December 31, 2013, 02:50:33 PM
Really appreciate your post. I used to be an ear only type but got a tach a while back and it really helps much like you said. Neither is better or worse but together create better results.
Thanks
And thank you!
Several points to ponder .First altitude and temperature most likely will be a factor in performance .I say with a certainty a saw will not run nearly as well in the mountains of Colorado at altitudes above 9,000 feet as well as in the flat lands of Ohio at around 850 feet .
If you alter the porting scheme of a saw the factory set parameters no longer apply .It may be higher RPMs or it may be lower depending .
A tachometer is indeed a nice instrument to own .I know many engine builders personally .Some build hot saws ran in such events as the Stihl timber sports .None that I am aware of relies soley on a tachometer .
Quote from: Al_Smith on December 31, 2013, 03:20:57 PM
I know many engine builders personally .Some build hot saws ran in such events as the Stihl timber sports .None that I am aware of relies soley on a tachometer .
Well said Al......this is where a stop watch timing cuts in a knotless piece of wood does the job. :)
Quote from: doubleclutchinweasel on December 31, 2013, 02:44:10 PM
Quote from: ZeroJunk on December 31, 2013, 01:06:22 PM
Fatcougar made a good point in the other thread . Modern saws will quit slobbering and two stroke under load at about 10,500 or 11,000 RPM. And, they will actually work fine that way, particularly on synthetic oil that doesn't carbon up so much.
But, that leaves you a window of 2,000 or 3,000 RPM to reach factory specified max no load RPM. Anywhere in that range will work.
I suspect saws tuned by ear are all over the place in that range.
Brown's Summit?
Ever make it over to Jordan Lake or Falls Lake?
I have fished Jordan, but not Falls. I usually go north, have a place at Phillpott in Virginia.
Add me to the column that says a tach is a nice tool to have. Adjusting just by ear, or only by tach, can be stubborn strongholds that ignore performance or safe operating limits.
Good comment also on changing conditions.
I have been told that the tachs are more important with newer saws, due to the changes in carbs, etc.
Philbert
I think it's more a case of preference than bickering.Noone is right or wrong the way I see it .
On one side is the crowd that are less experianced with tuning and rely on factory set specs .Then the old farts like me who have tuned just about every engine I ever fooled with by the seat of my pants .
There's really not too much difference than the great oil debate or how to file a chain .Methods matter little results are what count .
Hey, Chet.
Why did my "new topic" on AutoTune carbs show up as a post in this thread?
Never had that happen before...
Quote from: double clutchin weasel on December 31, 2013, 05:30:06 PM
Hey, Chet.
Why did my "new topic" on AutoTune carbs show up as a post in this thread?
Never had that happen before...
I copied the text over to a new thread. Seems to be okay now.
You want to delete the aforementioned AutoTune post from this thread?
Thanks.
Quote from: ZeroJunk on December 31, 2013, 04:08:18 PM
Quote from: doubleclutchinweasel on December 31, 2013, 02:44:10 PM
Quote from: ZeroJunk on December 31, 2013, 01:06:22 PM
Fatcougar made a good point in the other thread . Modern saws will quit slobbering and two stroke under load at about 10,500 or 11,000 RPM. And, they will actually work fine that way, particularly on synthetic oil that doesn't carbon up so much.
But, that leaves you a window of 2,000 or 3,000 RPM to reach factory specified max no load RPM. Anywhere in that range will work.
I suspect saws tuned by ear are all over the place in that range.
Brown's Summit?
Ever make it over to Jordan Lake or Falls Lake?
I have fished Jordan, but not Falls. I usually go north, have a place at Phillpott in Virginia.
Both those are lakes I helped clear in my youth. Please don't do the math!
Mr. DC Weasel, you know your stuff and provided some good info. But for a beginner, could you explain 2 stroking and 4 stroking.
Also, when the tachometer reading bounces around, do you select the high or the low or the average reading?
Quote from: Lnewman on December 31, 2013, 05:52:57 PM
Mr. DC Weasel, you know your stuff and provided some good info. But for a beginner, could you explain 2 stroking and 4 stroking.
Well...I can try!!!
If you hold a 2-stroke wide open, with no load, and lean out the mixture, the engine will get very smooth-sounding...TOO smooth, in fact. It will run too hot at this setting.
Now, if you keep richening the mixture, at some point the engine will start to sound differently. It will start to "sputter" or "burble". Another term for this sound is "4-stroking", as the engine starts to actually sound a little like a 4-stroke...which only fires every other rotation of the crankshaft, unlike the 2-stroke which fires every revolution.
It is important that a saw running with no load sounds this way, and that it smooths up quickly when loaded (in the cut).
The problem is that not all of us can identify this difference in sound accurately enough to use it as our soul means of tuning!
Does that make it clear as mud?
Regarding the tach reading, I try to read sort of an average, as there is quite a bit of fluctuation. But pay attention to the max, as a huge fluctuation might hint at some problem with the saw.
Quote from: Lnewman on December 31, 2013, 05:59:11 PM
Also, when the tachometer reading bounces around, do you select the high or the low or the average reading?
If your tach has a 'fast' and 'slow' setting, try choosing the slower sample rate to dampen out some of the variation.
Philbert
I just adjust so the saw idles nicely, revs smoothly and cuts well. Been doing this for years, periodically after splitting some big pulpwood down to size I'll pull the plug and check for a nice little brown, this is to me the best way to check the mixture, leaner produces a lighter color, white is BAD, darker means richer.
A plug check was how we always checked the tune on our 2 stroke flat track bikes, especially after a jet change. WOT run and shut it down.
All our saws run 32:1 and have never seized one, my neighbor did straight gas one but that is another story.
Quote from: double clutchin weasel on December 31, 2013, 05:30:06 PM
Hey, Chet.
Why did my "new topic" on AutoTune carbs show up as a post in this thread?
Never had that happen before...
I had merged your threads because they were both about tuning carburetors.
When I saw you started a 3rd thread on it I was wondering what was going on.
Since you asked for them to be separate that is where it stands and removed the merge. Seems like they belonged together from here though.
Quote from: jwilly3879 on December 31, 2013, 06:50:03 PM
I just adjust so the saw idles nicely, revs smoothly and cuts well. Been doing this for years, periodically after splitting some big pulpwood down to size I'll pull the plug and check for a nice little brown, this is to me the best way to check the mixture, leaner produces a lighter color, white is BAD, darker means richer.
A plug check was how we always checked the tune on our 2 stroke flat track bikes, especially after a jet change. WOT run and shut it down.
All our saws run 32:1 and have never seized one, my neighbor did straight gas one but that is another story.
Reading the plug is an excellent way to check the mixture. Thanks for adding this valuable information!
http://www.youtube.com/watch?v=29FiGmDQkaM
AdkStihl, Thanks for posting that video. For the first time I could actually hear and understand "four stroking"!
Great video, AdkStihl! Thanks for posting.
Good video Adk, lot of good info.
Mitch(mweba) is top notch in my book
Thanks for posting that Jeremy. My saws are all winding up ported with unlimited coils. You basically (at least I do) need a tach to really get the potential out of those saws. If your tach is jumping around wildly, make sure you are not near the limiters cutoff, as the electrical interference from that will drive the tach (and your ear if you mistake bumping the limiter as 4 stroking) crazy. It's nice to see so many familiar faces over here. You should make a video tuning Christine, as she is one of the sweetest sounding beasties I've ever heard
Thanks fro posting that video, AdkStihl. It's helpful to see it as well as hear it, and have the commentary as you go along. I have a much easier time hearing the difference here than I did on the Madsen's audio files.
I mostly use my ears for tuning, and I'm quite proficient at it. However I do have and use a tach. Wearing hearing protection while tuning by ear helps block out the distortion, and makes tuning by ear much easier.
As others have already said, each saw will reach proper air to fuel mixture at different rpm's. The tech sheet rpm's are a basic safe setting, but not necessarily the proper tuning.
Quote from: Andyshine77 on January 02, 2014, 12:09:14 AM
I mostly use my ears for tuning, and I'm quite proficient at it. However I do have and use a tach. Wearing hearing protection while tuning by ear helps block out the distortion, and makes tuning by ear much easier.
As others have already said, each saw will reach proper air to fuel mixture at different rpm's. The tech sheet rpm's are a basic safe setting, but not necessarily the proper tuning.
That is true. But, if you are repairing/rebuilding saws for other people and to sell there is not a lot of point in a lot of tweaking since you don't know what fuel and sometimes even what elevation they will be working.
As far as the complaint about the dealer having the saw rich he would have to be nuts not to tune them rich, IMO.
Quote from: Huskstihl on January 01, 2014, 09:20:55 PM
Thanks for posting that Jeremy. You should make a video tuning Christine, as she is one of the sweetest sounding beasties I've ever heard
Maybe when the temps return to anything above 0.
-9 here this AM without windchill factor.
Todays high is -2 with windchills around -35/-40
I don't like tuning / running a saw below 20*......not saying It hasn't been or cant be done, I just don't like doing it.
Looks like that's going to be a few days Adk. 7 here dropping below 0 before days end and staying that way through till the weekend.
Anything above 0 sounds good right now
Just checked a min ago.
-12 right now.
-31 with wind chill
smiley_confused
Quote from: AdkStihl on January 02, 2014, 10:31:25 AM
Anything above 0 sounds good right now
Just checked a min ago.
-12 right now.
-31 with wind chill
smiley_confused
We're at -6 with the wind, dropping down to around -25 or 30 with wind next couple nights. Been thinking of riding up to the camp near Old Forge in a couple hours after I get out of work, but you have me second guessing that now. :D
Not that cold here, but cold enough for me. Looks like about 5 above tonight and next Monday -10F no thank you.
From tuning with a tach to nasty weather in one fell swoop .I'm a hundred and twenty miles north of Andy and it's supposed to be 6 below tonight .Minus 18 on Monday .
Now there ya go .You get those cold dry temps those saw will run great .The operator doesn't fair well though .
Getting colder here too.....will have to richen those carb settings. :laugh:
Speaking of cold weather. Last February I had 3 brand new 550XP AutoTunes still in their boxes sitting in my shed with a temperature of -20 below. I fueled them up and it took all 3 well over 100 pulls on the rope with choke on to get them to start.
The auto tune processors was set at the factory at room temperature, but when I tried to start them at -20 below the settings were way too lean causing the hard initial startup.
A little lesson for the future.....get them to room temperature first :D
Here they are still basking in the cold.
(https://forestryforum.com/gallery/albums/userpics/21589/SDC11074.JPG)
(https://forestryforum.com/gallery/albums/userpics/21589/SDC11128.JPG)
Keeping with the weather, holy crap is it cold! -10 with -25 wind this morning and calling for much colder tonight!
Quote from: HolmenTree on January 02, 2014, 09:09:07 PM
Speaking of cold weather. Last February I had 3 brand new 550XP AutoTunes still in their boxes sitting in my shed with a temperature of -20 below. I fueled them up and it took all 3 well over 100 pulls on the rope with choke on to get them to start.
The auto tune processors was set at the factory at room temperature, but when I tried to start them at -20 below the settings were way too lean causing the hard initial startup.
A little lesson for the future.....get them to room temperature first :D
I hadn't thought of that, but thanks.
Guess I will grab the primer bottle, if I experience the same problem.
And about tuning: by ear, or by hand, if I have something to cut.
Quote from: JohnG28 on January 03, 2014, 10:08:54 AM
Keeping with the weather, holy crap is it cold! -10 with -25 wind this morning and calling for much colder tonight!
Where you at John?
I'm 1/4 mi from Canada ; 5 mi from Vermont
Lawdy you'd just as well be on the north pole .I think that's right up yonder at or near the story line site of Coopers"Last of the Mohigans" although the movie was filmed in North Carolina.
Quote from: Al_Smith on January 03, 2014, 12:06:55 PM
Lawdy you'd just as well be on the north pole .I think that's right up yonder at or near the story line site of Coopers"Last of the Mohigans" although the movie was filmed in North Carolina.
Ever heard of "Rogers Rangers"?
Took place right in my hometown. Along with tons of other French-Indian War stuff.
Lots of old military forts. Sunken warships.
Quite a bit of historical milestones took place around here.
Lots of underground railroad stuff too
Every summer a couple of guys from VT come over with metal detectors and scour the field directly across the road from my house.
They've been finding British coin and artifacts over there for years.
During the war, there was over 15,000 British troops camped out there.
The hill I'm situated on was/is called Prospect Hill. The British had a clear view of Lake Champlain which is about 4 mi away.
This is 5 min from my house.
http://www.hmdb.org/marker.asp?marker=48732
This is also 5 min from home. We used to play here when we were kids.
The old brick ovens were cool! HUGE!!
It hosted lots of parties for the older generations.
Now its unsafe.
http://en.wikipedia.org/wiki/Fort_Blunder
Well, to get the important stuff out the way first, I don't guess I get much sympathy because it is 43 degrees here!
I tuned engines by ear for a lot of years, race engines without any trace of a muffler. One of the reasons I can't tune by ear now, my hearing falls off radically in the higher pitched range and ain't none too good down low.
I just ordered a tach a few minutes ago. With the limiting coil on my saw it should work a lot better than my ears. Right now I'm running my saw very fat and leaving too much RPM unused. Feel better there than leaning the saw out. However being lazy I don't want any cut to take longer than it has to so good chain and good tuning are musts for my saws.(only have two right now after a six year layoff but I'm looking!)
I like the idea of getting close with the tach and fine tuning with the ears and time in a cut but I'll double check tach numbers after fine tuning. These days I need the crutch of instrumentation to be confident I'm not running a saw too lean. While I was ordering I got some H1-R on order and I'm going to buy all of my premium nonethanol at one supplier. Still have to adjust for day to day but I'm trying to minimize variables. Once I establish a baseline with the tach I should be able to quickly find that baseline after a major weather change.
Hu
It could change by just a tad from morning to afternoon some times .
Quote from: Al_Smith on January 03, 2014, 03:16:18 PM
I could change by just a tad from morning to afternoon some times .
Sure can change
Quote from: AdkStihl on January 03, 2014, 10:44:09 AM
Quote from: JohnG28 on January 03, 2014, 10:08:54 AM
Keeping with the weather, holy crap is it cold! -10 with -25 wind this morning and calling for much colder tonight!
Where you at John?
I'm 1/4 mi from Canada ; 5 mi from Vermont
I'm just outside Utica. Not near as cold as up where you are but plenty cold enough for me!
The last time I was up state in Watertown, NY,it stayed -47 for a solid week and was the deciding factor for the wife and I to pack our are bags to warmer climents ;D
Quote from: The Ripper on January 03, 2014, 08:18:50 PM
The last time I was up state in Watertown, NY,it stayed -47 for a solid week and was the deciding factor for the wife and I to pack our are bags to warmer climents ;D
Supposed to be -35 tonight in a near by town. Perhaps you've heard of Saranac Lake?
Anyway....I'm headed out ice fishing in the AM.
The Norwegians have a saying (Sawtroll correct me if I'm wrong), "there is no such thing as bad weather, only bad clothing"!
Quote from: AdkStihl on January 03, 2014, 10:44:09 AM
Quote from: JohnG28 on January 03, 2014, 10:08:54 AM
Keeping with the weather, holy crap is it cold! -10 with -25 wind this morning and calling for much colder tonight!
Where you at John?
I'm 1/4 mi from Canada ; 5 mi from Vermont
Hmmm you must live right next to a big lake. I drove by there on my way to college quite often.
Quote from: AdkStihl on January 03, 2014, 09:58:34 PM
Quote from: The Ripper on January 03, 2014, 08:18:50 PM
The last time I was up state in Watertown, NY,it stayed -47 for a solid week and was the deciding factor for the wife and I to pack our are bags to warmer climents ;D
Supposed to be -35 tonight in a near by town. Perhaps you've heard of Saranac Lake?
Anyway....I'm headed out ice fishing in the AM.
On my way to college, right next to Saranac Lake! (Paul Smiths) And yeah, it gets mighty cold there..... 4 hour classes outdoors in January, brrrrrr......