[bstrebe]

I''m wondering if anyone out there has any ideas on this. I have 30'' C&C that I purchased this summer. Under power I get vibration beginning around 1400 rpm and it gets worse with increased RPM''s. Sounds simple enough. However, in reverse, under full power, there is no vibration. The boat has a direct drive Atomic 4. I do not believe there is a reduction gear for reverse; so the prop should spin at the same rate for a given RPM as it does in forward -correct?

I had the boat surveyed and the shaft alignment checked. All seemed fine. The only issue the shaft log seemed a bit tired -understandable on a boat that is 31 years old. But nothing leaked and the stuffing box had just been repacked.

What I don''t understand is why in forward I get vibration, but in reverse I don''t. My thought is it has something to do with the 2 blade propeller.

Any thoughts are greatly appreciated.

Bill Strebel
C&C 30 #50