The stuffed crankpin was enough to bring the torque peak up a little higher in the powerband. Previously when I dogged the saw in the revs were lower, now the revs are higher and the saw is doing more cutting. The powerband is still wide enough to be a good work saw. I don't think the engine needs anymore crankcase compression, good thing, can't get the sealed bearings anyway.
I thought that the idle might get a little bit richer from the increased compression in the case blowing back through the carb, it did, in fact more than I had anticipated.
I had to lean out the low speed needle and it adversly affected the acceleration and torque off the bottom. I'm going to drill a small bypass hole in the throttle plate to allow more air at idle. Then turn the low speed needle out again to pick up the acceleration off idle.
I'll try the bypass hole rather than enlarge the cutaway in the throttle plate. The cutaway allows air to move both ways across the idle circuit, out, then in again, thus picking up extra fuel at idle. With the bypass hole the air can move through without 'double-dipping' on the idle circuit. The smallest drill I have is .75mm, so that's what I'll try first.
EDIT: I got to thinking about it and the extra crankcase compression shouldn't have made that much change in my low speed jetting. Then I remembered I had changed the crankseals because both of them had been damaged by sawdust getting under them. I must have had a small leak that leaned out the idle. - Now I have to properly set up the carb with good crankseals in the engine.
