Thermostat cover question

[JLRos]

Opened the thermostat covers in my johnson 1985 150hp (j150tlcos) and first, no thermostats, hey im in florida, still I’ll install them, but my question is about the covers because one of them have the open hole in front or “back of the poppet valve unplugged and the other was plugged with some kind of glue. So the question is hole of not hole, does the original piece comes with a hole that is suppose to be close or should remain open?

 

[racerone]

When the motor left the factory that hole was OPEN.-------There was a thermostat in there AND a pressure relief valve operated by a diaphragm.-------The diaphragm responded to water pressure on one side.-----And the other side therefor must be allowed to move thus the hole that is a vent.-----But as you have found people do wonderful things to cooling systems.

 

[Crosbyman]

so what is the story with removing ...or not removing thermostats in Florida ???

 

[F_R]

Our sea water is 96 degrees in summer and 60-ish in winter.

Besides, on most motors those thermostats change the routing of the water through the block according to need. But still, there will always say it isn't necessary.

At least it isn't like Lake Superior.