Sherwood M71 Raw Water Pump
I took the raw water pump off yesterday as it has been leaking a little oil. Actually, on a clean engine any oil leak always looks huge. I then noticed that the bottom weep hole had some dark staining. Since there's a spare on board I put it in, with a new impeller, and then looked into getting the stained one rebuilt. A rebuild kit plus a seal is ~$150, to that add shop time. A new one is $300. It's mighty hard to justify a rebuild!
I ran the engine after getting the new pump in. Wouldn't you know it, no water flow. Pulled the pump and opened it up to find that the new impeller I'd installed was the wrong size. It was close enough to fool the eye but not the gods of physics. It wasn't a total loss however, I'm getting really good at removing and reinstalling the pump.
Nellie goes through a heat exchanger 1/2" dia. x 2" long pencil zinc in about three months. I'm not sure if that's good or bad.
The valve lifter cover on the engine's port side is leaking from the aft, lower corner. Tightened the bolts.
