Originally Posted by Glowgeek

Both my 82's vibrate something fierce! Two of my Sbach cowl screws were loose and one was missing after just a couple of flights. This after using thin CA to harden the holes in the ply several times. Last night I drilled the holes to 1/8" and epoxied in the yellow inner nyrod pieces and cut washers from tygon fuel tubing to serve as damping washers for the screws. I've had good results before doing that but man, the vibes are out of control. The prop and spinner are in perfect balance and all fasteners have been double checked. Tuning is not overly rich and bearings are new.

Has anyone had good results by "clocking" a slightly out of balance prop to reduce engine vibes?