Water pump base doesn't fit flat 35 HP Merc

[rrwalker]

The water pump base is flat on the bottom while the housing surface on which it rests has three slightly raised areas between 1/32" - 1/16" thick around or near the three stud bolts. The gasket that goes between the pump and the housing surface is not thick enough to fill the void created by the uneven surface. I can't imagine the function of the raised areas. Can anyone tell me if this is a problem or if I should just bolt the pump down tight and forget about it?

 

[jslu]

Re: Water pump base doesn't fit flat 35 HP Merc

xxx

 

[jslu]

Re: Water pump base doesn't fit flat 35 HP Merc

The water pump base is flat on the bottom while the housing surface on which it rests has three slightly raised areas between 1/32" - 1/16" thick around or near the three stud bolts. The gasket that goes between the pump and the housing surface is not thick enough to fill the void created by the uneven surface. I can't imagine the function of the raised areas. Can anyone tell me if this is a problem or if I should just bolt the pump down tight and forget about it?

Your post might generate more responses if you supply motor serial no. and/or pictures

John

 

[oldman570]

Re: Water pump base doesn't fit flat 35 HP Merc

On some of the motors the raised part around the water pump lower plate are line up pins that the gasket and the lower pump plate fit over to keep them from moving when installing the pump impeller and the upper pump housing. the upper housing should be recessed where the studs/bolt go thru it and mate to the lower. Not sure what unit you have, but looking at it should tell if this is the case. JMO
Oldman570