RPMs/Engine Cooling

[LetsRock]

Is there a certain RPM thereshold that boats have in relation to keeping the engine cool? For example I was out this weekend and was traveling at about 23 knots at 3600 RPMs and I noticed the temp gauge a little higher than normal. I wasnt overheating but the needle was above normal. I then dropped it down to around 3200 RPMs and the gauge immediately went down to normal. Is there a certain point that the engine cannot keep up with cooling at the normal level?

 

[Summer Fun II]

Maybe your impeller is getting a little tired ??.

 

[LetsRock]

Maybe your impeller is getting a little tired ??.

Wayne - it was replaced at the begining of the season so I cant imagine that would be an issue.

 

[spfortjohn]

Thermostat sticking?