1998 C40TLRW overheat alarm

[Sushiholic]

when running full throttle, or near for a few minutes, the buzzer goes off. back off to idle and it goes away after 30 seconds. There are no real indications of overheat and there is a very strong stream from the pee hole, even at idle. could this be a sensor or is it possible there are problems with thermostat or passages ? if so, what is the recommended remedy ?

[robert graham]

The quickest and easiest items to check would be the thermostat and pressure control valve.....they can get mineral deposits and cause sticking.....pretty easy to clean each one in a mild acid and a toothbrush and re-install or replace with new ones. Next would be to drop lower unit and check the water pump....

[Sushiholic]

I know where the thermostat is.. where do I locate the pressure control valve ?

[99yam40]

the 40 does not have one.\

If stat is new or tested good, test the temp switch, and if pump has been replaced I would be concerned about passages plugging.
You can take motor apart to clean or try some chemical flushing

[Sushiholic]

thought I would provide an update. It was indeed the Thermostat. Now it will run full throttle until it runs out of gas without any alarms.

[boscoe99]

Thanks for the feed back. Much appreciated. Seldom received.