mercruiser 3.0 running temp

[rheipt]

i recently bought a 99 sea ray with a mercruiser 30 I/o board.. the boat was over heating hitting temps of 200 plus.. I replaced the impellar circ pump and intake riser. the boat is staying at 173ish now. I believe this is still kind of high seeing how I have a 140 degree thermostat in. at 173 it dropped though back to 168. whats every one else running for temps?

 

[achris]

That sounds about right.

 

[rheipt]

even with the 140 degree thermostat

 

[achris]

Yes. The temp on the thermostat is only the temperature at which it starts opening. It takes a higher temperature to be fully open (25?F to be precise) and in that time the water in the engine will have also increased in temperature.

So, a 140?F thermostat will not be fully open until 165?F... And that's just about what you're seeing. I'd say your engine's running about as cool as it can.

Happy?

Cheers,

Chris.......

 

[rheipt]

sounds good thank you!