Mercruiser temp

[pop pop]

I have a 1986 mercruiser 170 . what is the temp it should run at. my motor runs at 155% at idle and jump to 175 % at speed is this to hot. I know this motor has a lot of problems with head gaskets.What are our thoughts.

 

[bertg]

Closed cooling or Sea water cooled?
Bert

 

[kghost]

That is perfect!!

Enjoy.........

 

[pop pop]

Sorry the system is closed

 

[bertg]

pop pop For a closed system your temperature is in the proper heat range.
Bert

 

[pop pop]

Thanks to every one. that makes me feel a whole lot better.

 

[pugetsounder]

When was the last time you changed your impeller? 20 degrees seems like a lot of difference for a closed cooling system. Mine doesn't change more than 5 degrees from idle to wot with the same motor.

 

[pop pop]

Jst changed the impeller.