Pioneer saw runs rich/lean - HELP

[TonyM]

All right. I have a customer that brought me an older pioneer saw, think it's a P-71, that doesn't run. I could get it to run a little by adjusting the carb, but then it starves for fuel. Then if I richen the carb, it will start and run, and then flood out. I can go back and forth between the two, but can never get it to run good for more than a few seconds. I replaced the fuel line and filter, and it's a little better, but essentially the same. I loosened the gas cap thinking the vents were plugged, but it didn't help. The impulse is ported through the carb, so there's no line to go bad. I have told my customer that I suspect an air leak, and that it's probably not worth fixing the saw. I'm thinking crank seals or possibly the seal between the case halves. Any thoughts? I feel like fixing it just for the challenge, even though I don't think the saw is worth the time to repair it.

 

[TonyM]

Sorry, it's a model 2270, not P-71. I pulled the carb off wondering what condition the reed valve was in, and it looked fine. I took the recoil off and the sprocket cover/bar/chain and began to look things over. The bearings feel well used beyond their years. Both mains, and the rod. Funny, it wasn't that noisy when it ran, but maybe that's because it's so loud! I'm guessing bad mains = bad crank seals = air leak = erratic running.

 

[TonyM]

Yep, definitely bad crank seals. I pulled off the muffler, plug, and clutch. Then by putting my thumb over the impulse port at the intake, the reed valve allowed my to create a sort of air pump using the crankcase. I put a little squirt of some break away lube on the clutch side crank seal and started turning the flywheel by hand. I made a bubble blowing machine. So anyone looking for Pioneer parts?