Engine Overheat Warning at Low RPM'S

[hotajax]

Was trolling 1100 rpm's for a half hour or so, and the warning horn came on. The tell-tale stream was strong and steady, so I knew the water pump was not in play. Also had plenty of oil in the reserve tank. I kicked up the rpms for just a few seconds, and, voila, the overheat warning horn quieted down almost immediately.

So, is it my poppet valve, or more likely to be thermostat-related?? And how often should these components be replaced?

 

[plymouthgrady]

My $$$'s on the poppet. My '97 SWS II did the EXACT same thing-but we did all the expensive trouble shooting first.

 

[hotajax]

Plymouthgrady

Thanks for the 'fo. And go Red Sox

 

[NIGHTIDES]

POPPET..Just clean it no need to replace it..

 

[GT]

I might have just been lucky but I had similar problem, but Ihad new water pump, good stream, and recently changed (spring) t-stats. Everyone pointed me toward the poppet, saying a grain of sand or salt will make it stick. One suggestion was to flush the motor with fresh water for 30 minutes ( I normally give it a 10-15 flush), and it worked. No more alarm problems.

 

[plymouthgrady]

Good point. The poppet usually "goes" after the water pump is changed but the poppet isn't.

 

[Boats Rock]

I had the same issue. Removed the poppets. They had a jelly like build up under them that stopped the flow. washed them out and flushed the ports. Ran all season with no problem. I include this as a winterization task when I shut the boat down.