Replacing Yanmar raw water wear plate

[hlev00]

4JH4E, 2500 hours, 42' sailboat.

I am troubleshooting some issues with losing raw water prime after being out for a sail. When starting up after a sail to windward, no water comes out the exhaust. Either briefly loosening the raw water cover (after closing the seacock and cracking open the strainer cap), or a couple of revs of the engine, gets it going again. The boat has never had this problem before.

I've checked the Vetus above-waterline strainer cap. When I lose prime, the strainer is still full of water and does not seem to have lost any when I have lost prime. I've cleaned the Vetus anti-siphon valve. So I am now looking at the raw water pump. The wear plate seems a bit worn. I've seen suggestions to simply turn it over, but I am inclined to just replace it. If I do replace it should anything be done to prep the plate such as wetsanding with 600 on a glass plate?

Thanks,
Harry

[jamhass]

Just replace the plate. Also check the cover for grooves which can be sanded out as you suggest. Going this far, good time to remove the pump and give it a good rebuild, checking the shaft for scoring, new seal and bearings, etc.

[hlev00]

I have a new cover plate so will install that too. Good idea on touching up the pump. That will need to wait a bit but is easy access so will try to get to it before the season, otherwise put it on my winter list.

[deblen]

This link may help:https://www.cruisersforum.com/forums...mp-227192.html


Remove & check impeller for cracking.
Check the cam.
Cheers/Len