stihl 026 pro

[rick8809]

My 026 pro has a new plug ,carb.just rebuilt,exhaust screen is clean & I only use ethanol free gas. It starts well cold,sometimes it just shuts off after it gets warm,most of the time it starts really hard or will not start at all when hot.HELP!

[Furu]

The standard thing to say is check fuel filter, replace/how old is the fuel line, check the vent etc.

My experience with my 026 with a description very similar to yours was the saw carb needed the mixture modified.  The book gives you a good starting point on setting the screws but a good tach for fine tuning is a great aid.  Some folks can ear tune the saw but my ears are not what they once were and the tach makes it real easy.

[macpower]

What do you have for compression when warm?

[Knute]

I am wondering if it could be the coil.

[AdkStihl]

What you describe is the typical recipe for a bad coil.
Next time it gets hot and quits on ya, check for spark while its still hot.
No spark = bad coil.

Also, given the age of an 026, replacing the fuel line, fuel filter and impulse hose should be on your list of things to do as well. While doing this, check the intake boot for cracks, tears or dry rot....replace if necessary.

[Furu]

rick8809
You said that yours just shuts-off after it gets warm.  That could be interpreted different ways.  If it happens at WOT or partial throttle then my 026 experience was different.  If it just shuts-off if allowed to drop to idle when hot then read on.

Here are more details on my experience with my 026 many years back. (15+)
My 026  started fine, idled fine, ran great when cold until it got hot.  Once hot it ran great as long as I did not let an idle stabilize.  It would die (shut-off) if it was let to idle without rev'ing the engine on 2-3 sec intervals and would not start if it died.  If allowed to cool for 4-5 minutes then it would start and the cycle began again. I  replaced all the usual suspects, my Stihl service folks said that they were sure it was the coil because it fit all the symptoms of it. 

My 026 shut-off when hot only in idle not at higher throttle position including WOT.

Even though the service folks were certain it was the coil I did not believe it.  After reading how to adjust the 026 carb settings in both the service manual and the owners manual (different methods/techniques) I  adjusted the carb.  Wow I had a new saw.  Ran great never died everything was fine. 

15+ years later the saw still runs great, original coil still in it (the one the dealer wanted to replace).   3 bars and many loops have come and gone as well as filters and hoses. Bullet proof little saw.

I don't know how your saw "just shuts-off" but if my description is the same, try it.  If it shuts-off at WOT then it is different and probably is the coil. 
Deal with the simple before you go to the complex.

[joe_indi]

The wise men in the designs dept of Stihl gave the 026 a carb that has one part that is totally unsuitable for a pro saw. A plastic barb for the fuel inlet on the carburetor that has a habit of coming loose at times on its brass base.Running vibrations cause it to come a bit loose.Air is sucked in with the fuel, leaning out the fuel mixture while the saw is running under load. When this happens the saw stalls when the throttle is released.A proper carb setting cannot be done because of this problem.The remedy is to pull out the barb from its base, apply some epoxy glue and fit it back.To check if as loose barb  is the cause, disconnect the fuel hose and see if the white plastic barb rotates on its base.
I too was fooled by the notion that the 026 carb was a pig to tune till I figured out the usual cause of the trouble was this barb.A similar barb came on the Stihl blowers BR 320, 400, 420 etc.

Joe