Cooling system question

[aldel1962]

I have a 120hp mercruiser. Fresh water cooling. I have read that removing the thermastat can damage the motor. Is this true????

 

[bigskiohio]

Re: Cooling system question

my 120 merc did not have one it never had a problem was like that when i got it. I installed one this year when i ran it on muffs i dont think it ever opened
as the big hose got hot but i couldnt feel water in it , but i could be wrong.
i think water still circulates even though it is closed is that right?

 

[Hansolo99]

Re: Cooling system question

I had a force outboard that I had removed the thermostat on. It had a blown head gasket when I bought it. The mechanic told me they sometimes run a little hot and it was common on the 50hp outboards. He removed it and it ran fine!! Only thing is it will always run cold, could be a problem depending where you live.

 

[Chris1956]

Re: Cooling system question

Removing a thermostat in a motor will cause it to run cold. Efficiency will suffer, but the motor wil not be damaged.

Why do you want to remove the 'stat? If it is overheating, you might fix the impeller problem or heat exchanger problem, before it gets worse, and fries the 'stat-less motor.

 

[aldel1962]

Re: Cooling system question

I dont want to remove the thermastat. I bought the boat used and I dont think it has one in it. The temp gauge never seems to register any increase. The boat actually runs great, just curiuose about the potential damage I had read about. Thanks for the replies.

 

[Hansolo99]

Re: Cooling system question

Did you check the Temp-Sensor? Is it hooked up?? Is the gauge working? If it is not moving something is wrong. The engine runs cold, but the gauge should have some sort of reading.

 

[Chris1956]

Re: Cooling system question

Put your hand on the waterpump hose and see if it is warm after a few minutes running. If not, you should replace the thermostat. If it is warm, trouble shoot the temp gauge and sender.