266xp starts and runs good for about 10 to 15 min. After that it will lean out and quit. It can be restarted barely. You have to run it wide open because it won't hold an idle

SOURCE: dies running wide open

Hi

Check the air and the gas filtetrs.Change the plug with a new one with the same heat range.Adjust the carb H and L.
High speed H=2 turns and low speed L=2 1/2 turns

best regards savumihai71

SOURCE: I have a 36cc poulan chainsaw and it runs but not

I would go to Poulanpro.com with your model number and take a look at the manual for this tool and it gives you some troubleshooting hints on carb adjustments and other items to look for.

SOURCE: homelite saw runs wide open(homelite ut10520)

There is a recall on the UT models, all you have to do is call the costumer service center for homelite. they will give you a number for the closest warrenty center that will adjust you throttle cable free of charge. I went through two UT 10520's before i started researching the problem.

SOURCE: starts and then runs wide open.

SOUNDS LIKE THROTTLE NEEDLE STUCK OPEN CHECK THROTTLE LINKAGE STICKING OR RETURN SPRING

SOURCE: my 455 starts good and idles fine but wont go wide

Husqvarna recommends 50:1
1 gallon of premium fuel to 2.6 ounces of quality 2-cycle oil.
Lou
Clean the air filter and spark arrestor (muffler)
Try turning the "H" sdrew 1/8 turn CCW, if no better 3/16 CW.
this explains needle valve adjustment better than anything else I have seen.
Carburetor Adjustment by Madsens.com
http://www.madsens1.com/saw%20carb%20tune.htm
CW is leaner; to lean will destroy the saw. If over tightened closed (CW) the adjustment screw faces are easily marred; marred adjustments are difficult to impossible to set properly.
Clean the air filter; adjusting with a dirty filter can cause a run lean condition once cleaned and the saw run.
There are 2 wav (sound - idle & full – may not be highlighted) files that I find most helpful, I think you will too. HTH
Lou