Vibration ?

[Brian D.]

The vibraation is more noticable at about 1300-1500rpms it is not a steady vibration, just 1.5 seconds on and 1.5 seconds off.Does it sound like shaft alignment?3 cylinder diesel 36 foot catalina 1986Thanks, Brian D.

 

[Jon W]

Sounds Familiar

I have nothing constructive to add, but am curious what response you might get. It sounds like my reasonably new boat with the Universal M25 engine. My boat resonates slightly with a thruuuming? sound on and off every second or so. I figured it was some kind of harmonic vibration of the engine and boat structure and not too serious. I did think my prop shaft was a slightly loose fit in the cutlass bearing, but the boat was new and I don't have any experience on this point.

 

[Brian]

Re, My vibration

I replaced my 2 blade prop with a properly ballanced 3 blade and this vibration stopped.I guess my 2 blade was worn or out of balance