Neil A. Kruiswyk wrote:

Jeff,

    Not in this case.  It's definitely gear lash.  It happens at very low
RPMs, in my case anything under about 800 engine rpm (370 rpm at the prop).
You might want to call it gear slop since I have about 3/8" play at the tip
of the prop (in rotation).  Jim M is a bit less but he has a newer PSRU.

    Your solution is correct though....  just don't run there.

Neil

It is likely that what you all are hearing is resonance rather than just
backlash.  Tightening the clearances may change the resonant frequency
slightly but will not eliminate the problem.  Just don't run there.

Jeff Spitzer

Giving up and not running there is fine and works of course.

Maybe somebody needs to investigate the affect of changing
the springs in the clutch plate or trying a different 
clutch plate than the one Ross supplies.

There is another possibility and that is changing the timing
so it fires around top dead center at idle.

All this is best done on a test stand of course.

Paul Lamar
 
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