Johnson 50hp Thermostat

[johnnyhihat]

I have a 1973 johnson 50hp and i bought the termostat for it but when i pulled the termostat cover off i discovered that there was no thermostat or hi pressure value in the spots. someone before me removed them. do you recommend that i put new ones in or leave them out and just a new gasket which i bought new for the cover to put it back together. thanks again

 

[Joe Reeves]

Re: Johnson 50hp Thermostat

Whoever removed them was simply looking for a cheap temporary fix of overheating instead of installing a needed water pump kit. Install the needed parts that belong there.

(Thermostat Purpose)
(J. Reeves)

Many engines are considered high performance engines and demand a thermostat(s), and many smaller hp engines also require a thermostat for the following reason. The pistons actually distort/twist off round when running. The thermostat is required to keep the outer wall surrounding the steel cylinder, and the cylinder wall itself at a temperture to compensate for the distortion.

With the thermostat removed, the difference in temperture between the inside the cylinder and the water jacket quickly reaches a point whereas (in effect) you have a oblong piston running up and down a round cylinder, or vice versa. Bottom line is without the thermostat, the piston and cylinder wall could be damaged in a short period of time.

The thermostat in your car isn't there simply to have the heater function properly..... think about it.