Merry Fisher 655 Cutlass bearing wear.

[Bombastique]

Last year when the boat was slipped for cleaning I found that the cutlass bearing was so worn that the propeller could be moved vertically by at least 3 mil. That could explain the kettle vibrating on the stove all the time. 

I had the bearing replaced, not an easy job as to remove the bearing the shaft has to be removed.  To remove the shaft the rudder has to be removed. To remove the rudder the skeg has to be removed or in my case I had them just shorten it a bit by sawing it off as the cost was becoming crazy.

One year later and only 25 hours more ( there are only 250 hours on the boat from new) exactly the same problem.

This time I authorised a larger water lubrication supply, necessitating a new sea cock, pipe and spigot on the prop tube, bringing it up to 15mm. I also got the yard to leave a few mil of bearing projecting so that it could be pulled if it has to be changed a third time without removing the shaft.

It is thought that the 5 millimetre feed pipe is too small to reliably feed water possibly due to the slower speeds I normally run the boat (wife's requirements) or due to blockage from general debris in the sea water in the Solent.

I can confirm the boat is on a deep water mooring and we don't drive it on the mud. 

Has anyone any other ideas?

[vasko]

If the setup is similar to the sailing boat then you can remove the cutlass without removing the shaft etc. You just need a special bracket. Also is the bearing from all rubber type ? They are generally useless... also the root of the problem can be a wrong shaft allignment or engine movement a some of the engine feets can be loose or gone

[Bombastique]

Thanks for your comments.  
The merry Fisher has a prop tube with the bearing pushed into the end so no it is not like a sailing boat with a Y bracket.  There is no way to get a puller between the shaft and the bearing which is man enough to pull out the bearing. There is no access to the bearing from inside the boat with the shaft in situ.
The boat yard engineer has checked the alignment carefully when it went the second time,  and also is happy with the engine bearers. This is why we thought it might be lack of water flow to lubricate the bearing.
I have put another couple of hours on it today in the fine weather. So far so good!

[Bombastique]

The 2017 season went by and behold there is no appreciable wear in the cutlass bearing by last winter. The lack of water flow seems to have been the problem due to too small a pipe and fittings. 

I checked all is clear this week in the pipe and stern tube by a vigorous blowing down it. Lets hope there are no further headaches 
to contend with in that area. 

[donbelcher]

Just browsing and can now report a new cutlass bearing in 2019 and 2021.  This must be a record.