Vibration at 2200 revs

[fmilner]

I have a Yanmar 3YM20 on my SO 32i which had a new shaft, Volvo seal, cutlass bearing and alignment a couple of years ago.

The engine is smooth up to about 2200 revs then I get a vibration underfoot which dissapears at about 3000 revs and above. No vibration when I run in neutral.

Has anyone had a similar problem?

Frank

[tilo]

A lot can happen in the "couple of years" since the last alignment. It's probably something simple, like a poorly attached anode, or something attached to the prop. If there's no play in the shaft and cutlass bearing, then I would look at engine mounts next. Maybe one of them is failing. 

[fmilner]

Thanks for your advice. I have noticed a small dent in one of the prop blades so will straighten this out and see if it makes a difference. Failing that it sounds like engine mount replacement.

[bereboot]

Possibly a problem with the prop shaft?