1988 15hp johnson Thermostat

[ace1]

This may be a dumb question but--How do you tell if your thermostat is working as it should??

 

[coolguy147]

Re: 1988 15hp johnson Thermostat

take it out and put in hot water should open at around 140-145 degress faren.

 

[ezeke]

Re: 1988 15hp johnson Thermostat

Also check that the cylinder head is going to around that range whenever running; You can do it with a laser thermometer, or by putting fingers on the head for no more than a three count - if you can't hold them there for the count of three, it's overheating.

 

[ace1]

Re: 1988 15hp johnson Thermostat

Thanks guys- What kind of life span do they have. Im sure mine has never been replaced. The engine has only been used in fresh water, im guessin thats the only reason its lasted as long as it has. I hate the thought of burning up my motor over a 20 dollar part...