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1989 Johnson 20hp thermostat / temp. switch question(s)

Im guessing the rpm should drop not sure what it does irratic spark or cuts out one cylinder? Racer would probably know. The CD-2 has the slow feature.
 
OK so the powerhead is back together and running fine and no overheating (in the test tank at least).
Nice stream coming out the pee hole and exhaust water getting warm but not burning hot as it did back on the water.
I still have a lot of smoke coming out of the exhaust (see pic 1), and I noticed water seeping out of the exhaust cover on the side (pic 2), gasket not sealing anymore, so I took that cover off and need to find a replacement gasket now.

Would a seafoam decarb take care of the smoking? Or does it just nee some WOT action for some time?






BTW..... what is the purpose of that exhaust cover? (Just wondering because It seems to be running just fine without it)
 
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When I say it smokes a lot... looks like there's a lot of stuff in this exhaust.
I had crystal clear water in the test tank, here's what it looked like after running the motor a few minutes:



Guess a seafoam decarb / wot run will clean this up?
 
kimcrwbr1 said:
Make sure it is reaching WOT rpm it could be it is over propped causing it to load up.
Click to expand...

Yeah, it was running good on my last attempted test run, for a minute or two, until it bogged down and then only would run idle, and got very hot.
I ordered the exhaust housing replacement gasket, I guess I can't run it without it right?
 
Damn it. After all this work (water pump replacement, carb rebuild, new thermostat, water cover and head gasket replacement) the damn thing is still running hot.
It fires right up and runs fine as long as within operating temp, (I keep the laser on it to check the temp) but when it reached 150, which is hotter than it should be, it starts sneezing, and eventually stalls, or I shut it off before it gets too hot.
Not sure where to go now....
 
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