Cutlass bearings Yamaha 25mkII

[Pakele]

Hi there Yamaha 25mkII owners! I'm replacing my prop shaft and found that I have 3 cutlass bearings, all aft on the shaft... It looks like there possibly should be a 4th one forward... Can anyone advise on that? I have had a lot of movement on the forward end of the shaft since I bought it the boat, actually vibrating and rubbing the fiberglass at bulkhead into the engine compartment at higher revs...

 

[Ameseys]

I think there are only 2 bearings The cutlass bearing on the strut and another bearing forward, near the engine raw water intake. The only other point of contact I know is the stuffing box where the shaft exits the bilge. There is a diagram on page 6-8 of the manual:

http://tinyurl.com/4qpea4p

My boat vibrates a bit, but I've always blamed that one-cylinder engine. I do get some odd noise when backing hard, and I imagine that's the shaft. Others claim they reduced the shake by replacing the forward bearing. The original shaft is metric and that might complicate bearing replacement. I think this job requires pulling the shaft.

Richard

 

[Pakele]

Thanks... Cutlass bearings Yamaha 25mkII

Thanks for taking time to offer some help here... Oddly, I had looked at the Owners Manual a couple of days back and found the illustration on page 46... The shaft has been pulled and we found a bearing at the strut, at the exit of the shaft, in the stuffing box... but none forward... the illustration shows a Teflon Bearing forward. There was no bearing forward in my boat... There is a change of plan at the boatyard, I will now be going to a 7/8" inch stainless shaft leaving metric behind... and you are correct, there will be many items machined and refit to do the job! $$$Ka-ching!!! They suggest that the added rigidity for the length between the stuffing box bearing and the Trans-coupler should negate the need for the forward bearing... We can only hope they are right! Thanks again... it's good that this info goes on record for those in need in the future. I will advise progress on this project...

 

[Bob15082]

My 30 had a forward-mounted engine with a long 22mm (7/8")shaft. There was a bearing inside the cabin near the engine, and it was the only suspension between engine and the cutless bearing. The one-lunger engine jumped around a lot, and the intermediate shaft bearing kept the shaft in place. You might have a look at your engine mounts to make sure they aren't allowing the Yanmar to jump around too much.

Incidentally, there were a couple Y-29's sold in your area last year. If you ever run across one, I'd love to get a copy of the manual.

Bob,
yamahasailboats.org