50 horse water pump help

rbmille

Cadet
Joined
Jun 2, 2008
Messages
19
i have a 1982 mercury 50 h.p. all i feel out the pee hol is warm air. just curious if i may just not have it in the barrel deep enough.or what else could be the problem.
 

emckelvy

Commander
Joined
Jan 16, 2004
Messages
2,506
Re: 50 horse water pump help

If you have the motor submerged to at least 6 inches above the 'split' between the lower unit and the center section (AKA "exhaust tower" or "mid section") that should be plenty. If the water is just up to the 'split' that's probably not enough. If you have a set of "muffs" you can be sure that you're getting adequate water to the motor. With the motor running, you should adjust water pressure such that some water spills out the muffs.

At any rate, if you're sure the water supply (whether in barrel or via garden hose) is OK, you probably have a bad impeller and it's time to drop the lower unit.

Check the FAQ section of the iboats forums for impeller changeout procedures and/or pick up a good manual. Just don't run it any more once you figure out for sure that it's not getting water; you can burn up the powerhead in short order if you're underway, at speed, with no cooling!

HTH......ed
 

rbmille

Cadet
Joined
Jun 2, 2008
Messages
19
Re: 50 horse water pump help

well i just changed the water pump. but was wondering if maybe a missing rubber grommit between the pump and tube or something.

plus more questions to come.
 

emckelvy

Commander
Joined
Jan 16, 2004
Messages
2,506
Re: 50 horse water pump help

Check and make sure the impeller key didn't fall out of place. Also (more likely) check to ensure that the copper water supply tube engages the pump body as you're installing the lower unit. There definitely should be a rubber grommet in the pump where the water tube sits. Put a dab of grease on the rubber grommet I.D. and the water tube O.D. to help the 2 parts slide together.....ed
 
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