Stihl Carb Adjustment

tataylor

Hello - I just joined your forum and have a question. I need to adjust the carb on my "older" Stihl 015AV model. A manual for another Stihl I have says to turn out the L and H screws one full turn as a starting point and then adjust the idle speed so the chain stops turning. Is that all there is to it? It seems there would be another adjustment to the L & H screws after the initial setting. If anyone can give me an adjustment procedure it would be great. Also, if anyone could post a copy of the manual I am sure I will need it in the future.

Thanks.

Therrin

Um.... I dunno about posting a copy, but I'd be happy to send you a copy if you PM me with your email address.




*PS*
Mmmm, I just found a .pdf also that's a Stihl Carbeurator manual...just about carbs. How they work, how they're made, how to adjust them, etc... for stihl saws. I'll send you that one too when I get your email address.

Macgyver76

Therrin can I please get a copy of the Stihl carb manual via email? Thanx,Mac

Therrin

Sure!

First things first, Tataylor, I just got your 015 Manual in the mail, I'll ship it off to you...um.... on monday. So hopefully you'll get it sometime next week.

Macgyver76, yes, I'd be happy to email you the carb adjustment info and some other tuning stuff that I've got. I'll attatch it and send it off tonight.


If anyone else needs copies of the carb info, PM me with your email address.

tataylor

Hey - Thats great. I'll scan and get it back to you ASAP.

Therrin

I don't even have an 015. Just keep it.

leighwolf

Please if it is not too much trouble I would like a copy of the carb info, I just got a 015 av, clean the carb and fired up the first time. And then it seems to flood out when I restart. Recleaned carb and again runs real while but after turning off. Will not start again.
Leigh Wolf, Kansas lwol445@yahoo.com

Cut4fun

Basic carb tuning with sound waves.

Saw Carb Tuning

windthrown

STIHL 044, MS440, 046, MS460 - 13,500 RPM

Is not correct.

025, MS250, 026, MS260, MS361, 044, MS440, 046, MS460 all have a peak RPM of 14,000 according to my Stihl factory manuals.

Several comments on their method: you need a good L setting before it will idle at all. You need to fiddle with the L/A and the L screw interleaving back and forth on a Stihl. Idle and L setting are made at 3300 RPM on the above pro Stihl saws as well. Once at 3300, adjust the L screw rich or lean from the factory turnout for the highest idle speed. Adjust the L/A screw back to 3300 as you do that. It is an iterative process, and may take several times to get it right. The better the saw and more compression usually the easier and faster it will tune at the low (L) side.

Also before you tune your saw, put the bar on it and adjust the chain to give it proper unloaded drag for all adjustments. Whan setting the H screw I go through several more steps. Just setting the WOT RPM is not enough. I set the saw so that it burples (4 strokes), and is at the max rated REVs (unless the saw is ported, then I may go as far as 1k more in REVS). Then I do some test cuts WOT in a good chunk of wood. Often times the saw will bog a tad in the cut. In that case I will lean it out just a smidge. Usually that is enough to stop the bogging. You also want to listen in the cut for burples, or 4-stroking. Typically you want the saw sound to clean up when it is in the cut. If in doubt, set the saw a tad richer, as a rich saw will not overheat like a lean one will.

Also check your plugs. Do a cut at WOT for about 15 seconds and kill the saw from WOT. Then let it cool off enough to handle it, and pull the spark plug. It should have a medium to dark brown color. A light tan to white color is an indicator that your saw is running too lean. A black or carbon fouled coating usually means the saw is too rich. If your saw is tuned right but the plug indicates that it is running lean, check for air leaks. Also if your saw is hard to tune or runs weird, check for air leaks, poor or low compression, loose connections, leaking air filters, and gunked up muffler screens. Gunked us jets, gas filers and other carb innards can also cause your saw to run lean.

danschweitzer

hi a hows it going i have an 026 getting another next week only do around 12 or so days a year in the woods but i agree with what you say about the balancing of L and LA screws I ve had it running pretty good its bin wanting to go a tad high a bit peaky so I screwed the H screw out a bit I think I was still getting some runnaway so ive eased off the H some more sounds a bit rougher but going on wht i ve read this is better than the direct smooth full on peaky power is it? did have good power but my mane question is is screwing the H screw outwards leaning or richening I ask this caus when H was in quite a way it seemed rich? as ive come out with it it seemed to burn the fuel better? I ask caus the saw was running well but seemed to be aspiring higher than normal or I expected was nt conking like earlyer on the preveouse day. I ve been making adjustments for 2 days in the woods made the best ones whilst doing the felling cuts. any advise would be welcome

windthrown

Both the H and L screws run leaner when turned in (top of screw moving to the right) and richer when turned out (top of screw moving to the left).

As for H adjustments in the wood and out at WOT, adjustments are tiny. If you have limiter caps, put them back on when you are done. Otherwise the carb screws will run loose (they tend to back out, open up and richen up the mix). Similar with some earlier model Stihls; they have plastic sleves and shrouds that help to keep the carb screw settings set in place.

The idea is that a smooth running saw at WOT out of the wood is probably set too lean. You want it to burple/4-stroke some which means it is running just a tad rich (which is what you want). A smooth running saw in the wood WOT is a good thing, it should clean up as the revs drop. If not, lean it out a tad until it cleans up running WOT in the wood. I usually cut a few chainsaw cookies to get it just right. Out of the wood again at WOT, it should still burble. Again, the adjusting here is tiny and very fine adjusting of the H screw. A tach helps a lot so you can read the revs in the cuts and out and see what the tuning is doing to the saw. Also some saws, like a 361, are hard to hear for burple as the mufflers are so choked up. Modded muffers are easier to tune becasue they are LOUDER.

danschweitzer

cheers pal prob luky I did nt blow myn then but if i ajust it so I get max power in wood this should nt be to far out? if like you say all the sound is right and that it is nt too lean. I drilled a couple of large holes through the plate on inside of egsoust and a smaller one into the front do you think this will give it more power?

windthrown

Exhaust mods will give you more power, but they will cause the saw to run leaner with more airflow. So you need to re-tune them to richen up the H screw after drilling the holes in the mufflers, or they will burn up. Where you drill the holes depends on the type of saw and muffler design. I am going to post some photos of modified mufflers in my 026 saws on the 026 thread shortly.

danschweitzer

chears Thirmin, myn is around the 99 00 mark I think with a de compression valve

peter7720

Most Info you need is found at this site,the real full service manuals that's where I got mine pistoltech.com Cheers...

Dano

Sweet!

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Cheer's

Dano

http://www.treelove.com.au

Dano

Ha, like the kid in Bad Santa!

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Cheer's

Dano

http://www.treelove.com.au

jbcarey

Hi Therrin,
I just viewed this message and am interested in getting a copy of the carb manual
jbcarey1@comcast.net
Thanks

Tony Knight

Sorry bud, check Therrins status and you'll find he's an ex of the forum.

Cheers Tony