Originally Posted by tfrank
at 1800 rpm and 2000rpm, the engine temp seems to stay between 190 and 200 degrees. Is this an acceptable operating temp
I think this is a little too hot. Mine stays at 170°F even when running 2100 for hours. 180°F would be acceptable. Above? Not so much. But there is so many things to consider - first would be to crosscheck your temperature gauge readings with an infrared thermometer to see if the gauge is correct. Do you have any steam, even a little, coming out your exhaust
when the engine is up to temp?
will installing a lower temp thermostat make a difference?
I installed a 160°F thermostat just recently and just because. But I also replaced the heat exchanger
and the sea water pump
My hint after the usual suspects (partially clogged sea water strainer, scaled hoses, partially broken impeller, scaled/sooted up mixing elbow) would be to clean the heat exchanger
in diluted muriatric acid and flush the whole fresh water side with a good descaling agent.