On Aug 20, 10:22 pm, The Bewley Family wrote:
I have a Mercury hp outboard engine (1986) that will not pump water.
I installed (correctly) a new water pump and it still will not pump
water. Any ideas? Thanks! Bill

Not really sure. will it pump water at idle or low rpm? did you use a
genuine mercruiser water impeller?

The reason I'm asking is because a friend of mine installed an after
market impeller that was too soft. it would pump water at low rpm, but
when wound out it would quit. found out the compound in the impeller
was too soft, and at higher revs it would literally fold back and
allow water to slip around the housing. He then installed a genuine
OEM impeller and that cured it.

I've also heard of that happening with Johnson/Evinrude outboards.