engine vibration again

[e38 owner]

I am getting a vibration at higher rpms.
I have a rebuilt Martec Prop
I have a new Cutless
I have had the engine aligned and the Shaft checked
My mechanic said the engine mounts looked good during the alignment.

Do you think a flexible coupler between the coupler and transmission would help,
Thanks

 

[Frank Langer]

Your post says vibration again--does that mean you had it before and fixed it and now it's back? If so, can you provide more information about what caused it previously and fixed it?

Also, when I had a new transmission installed a few years ago, my tranny mechanic said he had aligned the engine to within four thousands. I had vibration after that installation, and redid the alignment myself and got it to within two thousands which improved the vibration significantly. The Ericson manuals indicate that it should be to within two thousands, so if it's not done to that closeness, that could be a partial cause of the vibration. Also, if I recall, the Martec is a folding propeller, and I understand that they are more prone to causing vibration, even when rebuilt and in good shape.

I have heard some criticisms of the flexible couplers, so it would be worth doing some research on them to ensure they don't cause other problems, or hide problems that should be addressed.

Frank

 

[e38 owner]

just a continuing effort to find the problem

I just can't seem to get this one solved. The alignment has been checked twice in the last year. At this point I am a two boat owner and this vibration is on my Non Ericson. It is a Santa Cruz with a Yanmar engine. A little different than the Universal I know all so well

 

[Gary Schroeder]

yet another direction to go ...... like there aren't enough anyway

I had that problem this past year, and the yard & I checked all those things. Additionally, the boat didn't seem to have it's old power, so an engine shop was called in and diagnosed a slightly leaky head gasket. Replacing that solved both problems. The symptoms came on so gradually and the engine still ran well enough that we did'nt start thinking of that kind of problem early on.