1985 Johnson Seahorse 8hp running hot

mikeyzx2

Chief Petty Officer
Joined
May 1, 2005
Messages
633
Hey ya'll like the new layout of the forum!

This is the deal......
This motor's running hot, I can't touch it for more than a second or two. It has a fairly new impeller in it, and I put a brand new spring, thermostat, and rubber seal in it, since there was none when I first got it. I pulled the head on it the other day and there was minimal stuff built up in the passages. I took the opportunity to clean the pistons and head and check out the bores. Looks almost brand new, even the carbon practically washed off with some carb cleaner.

I'm wondering if the thermostat's not opening fully or it's opening at higher temp. Best I can say is that when I dropped it in a pan of water, it opened when the bubbles started to form on the bottom not long before it starts boiling.

Any suggestions?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: 1985 Johnson Seahorse 8hp running hot

Did it cool before you changed the impeller?
Is any water coming out of the tellltale?Are you testing on muffs?If testing in a tank be sure water is above the pump.If you did the pump are you sure the pipe to the powerhead is hooked up properly?Is the water intake clear?Sounds like the thermostat is opening correctly.Is the thermostat in the right way around?
 
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