Hi there,
As you can see this is my first post here so i hope you don't mind me asking for some help?
I purchased a Stihl 038AV Super (eBay) May 2009 for logging on the country estate where i live (lots of fallen limbs and trees)I didn't pay a lot for the saw (so i thought (£150)) and was pleased it ran properly as it had been stood in a shed, half full of fuel for a few years.
The first time i used it, it got a fair old session - about 3hrs cutting a 24 inch ash trunk that had been down for about 4 years - but eventually it wouldn't idle when it got hot then wouldn't start.
SIEZED!
The piston rings had melted at one side and both piston and cylinder were badly scored. My local Stihl dealer/repair center estimated a £350 repair so i took it home.
I purchased a repair kit (cylinder, piston, rings, gasket kit etc. £70 - eBay again) thinking i was still only in for about the standard used price for an 038 and mine would have a brand new piston and cylinder.
After rebuilding the engine with the new cylinder and piston kit it started after a few pulls. Great. Ran it in for 10 mins on half revs.
Now to the log in the garden - the same 24 inch ash from last year.
Sliced off one piece and sat the saw down ticking over to move the piece out of the way and it cut out. AARRHH. Wouldn't start.
Fired a bit on furious pulling but that's it. The saw was quite hot at this point so i was right back where i started and feared the worse.
I let it cool and it started again fine.
So it seems that the cutting out is directly related to getting hot.
I took the muffler off - no scored piston - same with the carb side so I'm crossing fingers there has been no damage but of course the problem still exists.
I have read through many forums, threads and posts with lots of possibilities the main being running too lean due to an air leak somewhere.
So after that epic description here are my questions;
1) When the saw is sat on the floor for a while there is oil coming underneath from somewhere. Is this likely the chain oil tank/pump?
2) If the crank seals have gone how can i test this without specialist equipment?
3) I have noticed after it has been running and i remove the fuel cap there is a pressure release. It feels like the tank is creating a vacuum, is this normal?
4) Could a carb kit fix lean running?
5) Could it be the ignition coil?
I am not 100% sure it is running lean as the plug doesn't look too bad. Its a brown colour on the tip and pot and silky looking.
Any help would be great here to keep life in the 038
Cheers
