Is it Overheating?

[Old Man Grizz]

I replaced the impeller in my 1959 Johnson 35 hp.
i started it on the Trailer while it was in the water. I know the water needs to be about 6” higher than the impeller to make it work. The engine ran fine, but was hot to the touch on the head. My question,(FINALLY!)
how can I tell if it is working?
what will happen if it isn’t? (I know, it gets hot!) but how can I tell if it’s overheating?
Thanks Very Much for your time, and any ideas!

 

[Chinewalker]

If it's pumping properly, a heavy mist of water will be coming out the hole midway up the back of the motor leg. Your motor's cooling is thermostatically controlled, so it will feel warmer than an earlier 35 without the stat.

 

[oldboat1]

An excuse to get an IR tester. Temp. should be 130-140F or so. 160 is too hot.

 

[Old Man Grizz]

What is an IR Tester??
thanks!

 

[DouglasW]

Handheld InfraRed (IR) temperature sensor.

https://www.amazon.com/HDE-Accuracy-Non-Contact-Temperature-Thermometer/dp/B009RUPQGW