1956 Evinrude Lightwin 3HP - Overheating

[chad101]

I have heard that the older Evinrude motors were designed to run slightly hot. But, what is too hot?

I replaced the impeller and started up the motor in a trash can. After allowing the engine to run at full throttle for 5 minutes, I used an IR gun to get some temperature readings.

Directly next to the spark plugs: 198 F
Engine side (none exhaust side): 170 F
The exhaust plate: 498 F

Not sure if this normal. I?m a little worried; I know this motor does not have a tale tell, but I can see water drizzling out the exhaust relief holes.

What is the normal operating temp for these small engines?

 

[Chinewalker]

Re: 1956 Evinrude Lightwin 3HP - Overheating

That doesn't sound too bad. The exhaust plate is just that - deflecting the exhaust. There is no cooling plate over the exhaust plate on those motors. Invariably the exhaust plate's paint is burned.

The head has very little water circulation, so the plugs getting warm is normal, too.

As long as you're getting a good mist out the relief holes in the motor leg, I'd say you're good to go.

 

[tmcalavy]

Re: 1956 Evinrude Lightwin 3HP - Overheating

You should be able to put your hand on the water jackets when its running without frying yourself...but don't confuse the water jackets with the exhaust...that will be too hot to touch.