"Greg" wrote in message
...


It will not fail on a trailer. The boat needs to be pushing
water to be running hard enough to overheat.

When you measured the water pressure, was that sitting at idle, or while
running? Does the motor have a "pee hole", and if it does, can you see a
good stream of water coming out?

I am wondering if the problem isn't some factor involving the boat, like
maybe the motor is mounted too high and the pump is sucking air. That could
be a problem when the boat is up on plane, but shouldn't be a problem while
sitting idle.


I really think this is just not pumping enough water and under a load it
overloads the ability to cool. Simple huh?
You can see why I really want to swap the whole damned foot.


The first thing I would try is to remove the foot and disassemble the water
pump. Clamp on the "ear muffs" to connect the water hose and turn the water
on. The pressure from the hose should send a good stream of water into the
pump housing.

If that looks good, then the next thing I would try it to connect a hose to
the water tube that goes up into the motor. You should be able to come up
with some combination of hoses and fittings that will allow you to clamp a
hose to the water supply tube. If you want to get really fancy you could
throw a T on the faucet and connect a pressure gauge so you can see how much
pressure you are putting into the unit. Turn the hose on and see how much
water flows. If you have your engine water pressure gauge working you can
see how much hose pressure is required to get the desired engine manifold
pressure. That might tell you a lot.

You mentioned that they had to replace a broken housing. Was this a
thermostat housing? Do you have the old one? I am thinking that you might
be able to take the broken housing, modify it to add a hose barb and use it
to back flush the upper unit. If there is a blockage in the upper unit
someplace then creating a reverse flow might wash it out.

I suppose the worst thing is that you had some sort of critter get into
the cooling system when it was really small, and then grow to such a size
that it is creating a blockage and it can't wash out.

Rod