Home › Forum › Ask A Member › Head and cylinder temps on 58 Johnson Super Seahoese 35 › Reply To: Head and cylinder temps on 58 Johnson Super Seahoese 35
Yeah, those temps are high, are you sure your temp gage is working properly?
How are you running, testing the engine? On the boat in the water? In a bucket? On a flushette? These engines can be fussy when not running in the water on an actual boat. Make sure the water level is high enough in the barrel to bury the gearcase completely in water, up over the gearcase/exhaust hsg joint. Flushettes rarely work properly on these engines as well.
Did you run the engine before doing the water pump job? If so, did it cool OK then? You replaced the impeller, did you use an OEM impeller or aftermarket? Are you sure you got that gearcase installed correctly, this is real tricky having to line up two water tubes and the driveshaft.
Is any water/fine spray coming out of the exhaust relief while running? Have you had the thermostat cover off? Keep in mind that the thermostat, cup, spring, and relief valve must be in place and working properly or else cooling water can short circuit out of the block without circulating properly. Try running the engine with the thermostat cover removed, you should see water bubbling up out of the thermostat pocket/housing. This is a complicated cooling system, alot of things have to be right or it won’t cool properly.