Boat Runs Hot when going above 3000rpms, please help

[LevIsak]

I just bought a 95 maxum 2300 sc, i have 5.0l mercruiser alpha 1 gen 2, with a closed cooling system. i just had it serviced for pretty much everything impeller, new carb, etc..

she idles fine and cruises at about 2800 to 3000rpms at about 160 degrees, if i go above 3000rpms she starts to climb in temp almost reaching 200 degrees.

i cant figure out what it is, niether can my mechanic ive spent over 2grand on her already please help

 

[steve201]

Re: Boat Runs Hot when going above 3000rpms, please help

well..there are a few things to check...is the heat exchanger clear at the tubes???....what thermostat did you put in?? is it new???......most of the time it's the impeller...doesn't mean it was installed correctly...I'd pull the outdrive and check that too.....


Steve

 

[dodgezilla04]

Re: Boat Runs Hot when going above 3000rpms, please help

its quite possible there is an air bubble in the thermostat housing not allowing coolant to contact the tstat, that will insulate the tstat to some extent and it doesnt open when it should...

 

[Lil Dickey]

Re: Boat Runs Hot when going above 3000rpms, please help

What is the source of this bubble? Is it introduced when replacinging the thermostat?

 

[steve201]

Re: Boat Runs Hot when going above 3000rpms, please help

yep..that could cause the heat...however it could also be the risers are crapped up..may need to replace those..


Steve