So I took tin off the engine one piece at a time, then the drive shaft, then the flywheel screen with no luck. The noise goes away at idle. Gets quite loud just above idle then changes pitch as throttle is increased. I'm pretty sure it's coming from the front (of the tractor) but I can't pinpoint it with the redneck stethoscope.
I have .010" crankshaft end play.
The motor doesn't shake badly, I don't think.
Could it be counter balance weights or possibly the ACR?
Or maybe the governor internals?
Anyway, looks like I'm going to be pulling the motor.
