Prop shaft clearance issue

[Benlieb]

Hi folks,

Went to align the engine today, and noticed that the shaft log through which the shaft passes is only a tiny bit bigger than the 1" shaft. Normally I see more clearance around the shaft. I think this explains the loud banging I heard above about half throttle. This is a cd28. Anybody who has dealt with this issue? My first thought was that in the original setup maybe the motor was hard mounted? Or had a 3/4 shaft?

Thanks for any insight,

Ben

[Jim Walsh]

The shaft should pass through the shaft log and the cutlass bearing with no discernible play. Do you have a photo?

[Benlieb]

No photo, but yes that is what I found, no room for play or to account for engine movement even. I set the Yanmar I installed on flexible motor feet, and am wondering if I should do away with those and hard mount it.

[Benlieb]

I guess I'm asking how is your engine mount situation. I need something to compare my custom stuff to.

[Sea Hunt Video]

The July/August 2016 issue of Good Old Boat has a good article (4 pages with a lot of photos) on issues related to the stern tube, prop shaft, etc. For someone like me, who knows very little about the subject matter, it was an educational article.