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1971 40 hp evinrude overheating

mandy

New member
I replaced the pump housing a

I replaced the pump housing and impeller. Water comes trickles out at idle and no water (only steam) is seen when the motor is ran. I removed the lower unit and attached a garden hose to the copper tube-- water seemed to flow abundantly.

Any Idea why the pump won't pump? Thanks Mandy
 
" PS. I replaced the housing

" PS. I replaced the housing above the impeller, the impeller and the thin aluminum plate below the impeller since some residual water left in it over the winter caused the housing to crack and the aluminum plate to bend. Mandy "
 
"Mandy.... If everything is fi

"Mandy.... If everything is fine at the powerhead, I would assume that you did not seal the surfaces of the water pump when you installed the new components. The surface under the bottom of that plate, and the under surfaces of the imoeller housing that contacts the plate should be sealed (coated with approx a 1/8" bead) of Marpox #1000. If it is not sealed properly, it will draw air.

If your problem exists only when the engine is on the boat, and when you are under way, I would have a tendency to think that you may have the wrong length shaft engine for the boat, The caviation plate (the plate just above the prop), should be approximately 1" beneath the keel of the boat.... the bottom of the boat at the center of the transom. No deeper than that, and most certainly not above the bottom of the boat, less the water intake will be exposed to air when under way. Let us know what you find.

Note that Marpox manufactures other sealers but do not use them. Use only the #1000.

Joe
"
 
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