I think I know the answer to this question but wanted to put out to the group. I have a 1997 Catalina MKII with a M-35 30HP Universal. The cutless bearing had to be replaced 4 years ago, and then again the following year. Upon doing some research I decided to replace the shaft. The boat had the initial bronze shaft so I replaced with a stainless and replaced the cutlass again. I was able to get the engine aligned after the shaft replacement and enjoyed a nice summer here in New Hampshire. After hauling this fall the cutlass is loose again. Tracing the root cause back I looked at the motor mounts. Upon inspection of the motor mounts I can see light between the pin and the rubber on 3 of them. In my mind this indicates that the rubber has compressed and not holding the engine properly. There is the typical vibration at low RPM that all universals get, but it goes away will slighty more RPM. I have attached a few pictures. Curious if you all think I have the correct diagnosis? Thanks for any feedback!
I would suspect motor mounts too with that kind of bearing wear, but I don't have a lot of expertise to offer in the area of mounts.
How many hours on the engine?
Have you had the pleasure of wrapping a lobster trap line? That can bend both the shaft (you have a new one, so that's an unlikely the root problem), and, put the prop blades out of alignment. Accutech in Dover NH helped me with my previous boat prop after I wrapped a line.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
The motor has about 1,400 hours on it.
I have been lobster pot free for a few years so that is unlikely to be the problem. The last one was fathers day quite a number of years ago. I got a wetsuit shortly thereafter...