Atomic 4 water pump

fullandby

Junior Member
OK, now I have myself worried. I came here to see if I could find out information on finding an O-ring replacement for the water pump cover plate and have been seeing threads about the impeller shaft removal. As it turns out the shaft came out on me when I replaced the impeller. I had no idea there was a snap ring on the shaft nor do I remember there being one on the Ericson 32 A4 engine that I first sailed on. Shows you what you forget after 15 or so odd years. So what is the general consensus on this? Do I now have to pull the pump and replace the shaft bearings?
 

tenders

Innocent Bystander
The snap ring keeps the impeller on the end of the shaft. It's replaceable if you've lost yours, but opinions are mixed on whether it's really necessary. Without it, the shaft can wobble a bit fore and aft, which might reduce the life or effectiveness of the seals.

The cover plate, by capturing the impeller, keeps the end of the shaft opposite the impeller from coming out. Nothing but friction holds the shaft in when the cover plate is off and it isn't unusual for it to pop out when replacing the impeller.

If your cover plate had an O-ring then Moyer can get you another. If it doesn't have an O-ring, a lottery ticket is the right thickness and almost the right size for the paper gasket that otherwise goes there (no cutting necessary). The impeller will wear down any unnecessary paper in the chamber and eventually will blow it out the exhaust.
 
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