On Jul 4, 10:24*pm, "James H." wrote:
On Sun, 4 Jul 2010 22:15:32 -0700 (PDT), harry wrote:
IT sounds like the engine is unbalanced

Yes. Something went unbalanced but I checked (visually only) the blade
itself which seems to be all nicked up but no worse than it has been for a
loooong time.

therefor some rotating part has broken off or the crankshaft is bent. *

It could be a bent crankshaft. I guess. But, I've hit far worse than what
made this happen this time as it happened all of a sudden on me.

How would I know if the crankshaft is bent?


Pull the plug (safety) and rotate the blade around: Measure clearance
between tip and housing at points 180 degrees apart. If same, not
bent. If different do the same check using the opposite end of the
blade for the measuring. If it is the same, i.e., diffenent 180
degrees apart and the difference is the same as your first check,
then the odds by far favor a bent shaft, not a bent blade. For
further proof put a new blade on and use that to check.

snip remaining - answered down thread

Harry K