"GOP=Greedy Old Perverts" wrote in message
...

"bob" wrote in message
oups.com...
I have 1998 Glastoron Se175 that I thought I got a great deal on. The
2nd time the boat was taken out it overheated to the point it warped a
valve and melted my wiring harness. I tore it down and had the head
machined/valve job and rewired the unit. I replaced the nub, where the
impeller used to be and the thermostat. After extensive time on the
unit, I got it running very well in my driveway with the mufflers on.
When I take it out, it runs very well, but runs very hot at high speeds
190-205. The guy that owned the boat before me took out the overheat
horn. When I cut the speed to 3000RPM the temp drops back to 180s.
If I sit and idel for ~2-3 minutes the temp drops to the 140-150 range.
After close inspection (I bought the boat w/o seeing it for $3700 when
it should have been worth about $9k), I notice the prop shaft was bent.
Could the eleyptical rotation of the shaft be causing enough water
interferance/low end shacking that the unit cannot get water at high
speeds? I will replace the shaft, but fear the problem will remain. I
ideas on the overheating issue and suggected paths to resolution?


What kind of engine?



Some guesses on an I/o

Impeller
Thermostat
water pump

and my best guess - hose leak, crimp or collapse.

I would go for the crimp first, trace the hose from where it comes out of
the outdrive/ transom and make sure it is not pinched or crimped where it
bends. Good chance there is some sort of restriction on this hose.

In autos the plies of radiator hose will sometime separate and if it is on
the intake side of the waterpump they can get sucked in and block the flow.