Prop Shaft Vibration

[donvanv]

I am new to my '98 Oceanis 36cc. It was purchased in March and I'm still getting to know how she handles. I am getting some vibration from the prop/shaft at over 2000 rpm and just wondering how much (if any) vibration is acceptable. It has a Volvo stuffing box and I can visibly see the slight movement causing the vibration when running at the higher RPMs.

I had a survey and I watched the surveyor manually move the prop while it was out of the water and check for alignment; which he did not find. It is a 3 blade prop.

I was told the engine was rebuilt, so it only has a few hundred hours on the engine. So if the engine was taken out and replaced, could it be out of alignment causing the vibration.

Or, am I just being anal about this and some slight vibration is usually normal and acceptable?

 

[DougM]

It's hard to determine how much vibration is too much, but there is always some inherent vibration due to hull harmonic characteristics and from the prop blades as they pass the skeg. It doesn't hurt to periodically check shaft alignment and cutlass bearing as a part of routine maintenance. Also the engine can move slightly on its mounts or settle over time.

 

[Captn TJ]

It's hard to determine how much vibration is too much, but there is always some inherent vibration due to hull harmonic characteristics and from the prop blades as they pass the skeg. It doesn't hurt to periodically check shaft alignment and cutlass bearing as a part of routine maintenance. Also the engine can move slightly on its mounts or settle over time.

With the original three blade prop (which I assume is not fouled). As suggested I'd check cutlass and alignment first especially if alignment was checked with mast not tuned. If that is within tolerance then mounts should be checked. However, while I'm not an expert at this my sense is that if it where the mounts the engine would have a lot of vibration. Lastly if alignment is spot on and mounts are in great shape then potentially shaft out of round?