1963 johnson overheating on one side

[tamuben1]

1963 75 horsepower Johnson (V4AL-15E)

I started my engine in a bucket of water the other day to make sure it was idling correctly and noticed that after 2 or 3 minutes the starboard side of the engine was considerably hotter than the port side so I immediately shut it down because I thought it might be overheating. The port side felt like a "normal" running engine, the starboard side felt way too hot. I am going to borrow an infrared thermometer tomorrow to see what the actual temperatures are. What temperature should the heads and thermostat be at? Should the heads be the same temperature? Is there a way to see if the impeller is working properly without removing the lower unit (it was replaced 6 months ago)? Would a bad thermostat allow one side of the engine to be cooled but not the other? Can someone give me an outboard cooling system 101?

thanks

 

[Daviet]

Re: 1963 johnson overheating on one side

How deep is the bucket, for proper cooling the water should be 6-8" above the water pump. With a low water level you could cause cooling problems.

 

[tamuben1]

Re: 1963 johnson overheating on one side

the barrel is about 4 feet deep. I have the engine sitting in water at least as deep as it sits in when it is at the lake.

 

[Fuzzytbay]

Re: 1963 johnson overheating on one side

Ons side of the motor, should be warmer. The outer water jacket is on one side, the exhaust ports on the other. The exhaust side will be warmer.