1978 55hp rude overheating

[brother chris]

My motor overheating alarm has been going off once I start it and run it for about 2 minutes.
So, to diagnose the problem, since I installed a new impellor and thermostat last year; I took the thermostat off and tested it. It opened at 145 degrees, so the thermostat is fine. I also started the motor without the thermostat and the overheating alarm did not go off.
So, I went and started the motor(after re-installing the thermostat) and after a couple minutes, I could not put my hand on the motor, it was too hot!:^ And the overheating alarm did not go off.
If I have a good P-stream and the thermostat works properly and the impellor is fine, then why would it overheat?
Any ideas would be much appreciated. I want to go boating tomorrow, so hopefully I can figure this out tonight.
Thanks,
B.C.

 

[brother chris]

Re: 1978 55hp rude overheating

bump

 

[jtexas]

Re: 1978 55hp rude overheating

Really only one thing could cause it to overheat: friction. How's the compression? Have a cylinder starved for fuel maybe?

Pee stream only indicates that the pump is pumping; could still have an obstruction blocking off the top end of water flow.

 

[brother chris]

Re: 1978 55hp rude overheating

Thanks for the reply jtexas.
I took the boat out yesterday and it seemed fine! It ran cool and consitent. Maybe running it "not under load" caused it too heat up a bit more than normal...I'm not sure.
But everything seems to be just running how it should.
Thanks,
B.C.