Stihl 010 av has got me stressed out help me!

[sprintmotor45]

Working on a stihl 010 av for a friend and its got me stumped. Here is what it does; will not start on first pull every time but sometimes does. Runs for 1 or 2 seconds at an idle then dies. When it dies it almost sounds to me like its loosing its spark. choke it and it will not start when warm. Opening the throttle wide open and will not take of as easy as starting at an idle. Here is what I have done; Cleaned carb, have played with high and low screws. starts best with them roughly set at 1 to 1.5 out. adjusted diafram leverup and down no change. checked carb isolater between carb and crankcase for flatness. It was warped, corrected that, new gaskets. fuel tank vent is open, new fuel line, compression is 110. Set points at .015 and air gap on pickup at .008. New spark plug. When I check spark it is nice and blue every time. Whats wrong? any ideas? It really acts like ignition cause it dies just like you killed the switch.

 

[pioneerguy600]

If the compression is really 110 psi then that is the likely cause of it not restarting, a engine with that low of comp is usually hard starting. A comp of 130-140 is common for these saws and the start easily with comp that high.

 

[sefh3]

Pull the muffler off and take a look at the piston. I'm betting it's scored or you have a stuck ring. This will cause a hard starting saw. After it runs and cuts out, pull the plug out and check spark. If there is no spark the condensor has gone bad. Usually they refire once the condensor cools down.