Engine Vibration

[Al Dancho]

I recently purchased a Catalina 30mk111.It has a Universal 25. Between 950 RPM and 1050 RPM the engine vibrates. Belowand above those RPMs the engine is smooth. Should I be concerned and arethere be any remedies?

 

[Richard Randall]

vibration

Generally if you have vibration in such a limited rpm range, it is something else in the boat (other than the engine itself) vibrating in resonance with the engine at this rpm. This other vibrating object makes it seem as if the engine is vibrating more at this rpm. Check to see if the noise is coming from a vibrating hatch cover, cabinet door, bulkhead, etc. Also, check the engine mounts and other non-rotating parts of the engine to make sure they are not loose. You should be able to eliminate the problem by tightening up the vibrating object, or putting in a shim of some sort to dampend this secondary vibration.

 

[Doug]

Dont listen to bad advice!

The vibration you have stated is more than likely bad prop shaft alignment,which needs to be taken care of.Usually there are alignment proceduresoutlined in the engine manufacturershandbook.....otherwise a qualifiedmarine mechcanic should look at the problem...failure to do so couldresult in engine bearing wear!