1992 mercury classic 40 hp

[fivespot]

where is the thermostat located on this motor 4 cyl 40 hp 2 stroke oil injected ?

 

[racerone]

I don't think there is one on that model.----Serial # of your motor ?

 

[fivespot]

0c160923

 

[fivespot]

the engine temp sensor went off today and the water from the tell tale was very warm.I am running in fresh water and it took about15-18 min for alarm to sound

 

[Faztbullet]

Change the impeller.....

 

[racerone]

That family of engines never used a thermostat.-----Time to do a compression test.--------Change impeller every 3 years from now on.

 

[fivespot]

did compression check all cylinders between 100-110 lbs compression

 

[fivespot]

Are these compression readings within acceptable limits ?

 

[racerone]

I would pull bypass covers and have a look at pistons and rings.----Then again some gauges do read different than others.-------Is motor cooling properly now ?.

 

[fivespot]

going to change water pump and try again on week end I will post results. thanks for the input racerone

 

[fivespot]

are the bypass covers you are reffering to the exhaust plates on the left side of the motor looking forward over the motor toward the bow ?