I have an older Evinrude 70hp(90 model, I believe) I have a Serial
number, but don't know where to find for year.

But my problem is the overheat alarm seems to sound frequently. But if
you shut the motor off for just a few minutes it shuts off. Then you
can run it for another while longer before it does it again. But in
now is occuring more frequently than it was before. I just had a new
water pump put in at the beginning of the season and new temp sensor
and sending unit last year.

I am thinking I need a new thermostat, but would like some advice on
what to check and do. Please help me with some more info on fixing my
problem.

Thanks,
Nick