Overheat Alarm

[Jason Mann]

1996, Johnson 115 Cross flow. 65 hours on new power head. Overheat alarm (steady tone) turns on and stays on after approx 5 minutes of motor running. I dropped the lower unit already, water pump looks brand new. Pulled thermostats and tested them in hot water, they both opened at approx 170 degrees. Ran motor with thermostat cover off and water is flowing through block. Pulled temperature switches and tested them in hot oil, received continuity from sensor to wire at approx 207 degrees. Now I'm stumped. Somebody help, please!

 

[Boobie]

Have you tried a different overheat alarm ??

 

[Jason Mann]

I have not. Please correct me if I'm wrong, but if the alarm was bad wouldn't it go off when I started the motor? I feel like since it alarms around 5 minutes into the motor running that something is triggering that to happen.

 

[johnnygjr]

do a compression check

 

[flyingscott]

Get a temp gun and see what the actual temps are. Aren't those thermostats supposed to be 143 deg