overheating

[scully222]

I have a 1980 9.9hp Johnson, that I recently changed water pump on. Took it out for a ride and it ran good except I noticed more smoke than usual and when I touched side of lower unit, it was hot to touch.Couldn't hold hand on for more than a few seconds. Water was coming out of pee hole as usual and it was cool. Didn't want to fry engine so I babied it back home. I'm going to buy manual and take apart again. Do you think that water tube is not seated right?

 

[tashasdaddy]

Re: overheating

possible, or the tstat needs to be changed, just because you have stream, does not mean the tstat is opening, and cooling the motor.

 

[ezeke]

Re: overheating

When you say lower unit, are you talking about the midsection or the gearcase? The midsection should have water in it to cool the exhaust tube.

 

[scully222]

Re: overheating

I was touching the mid section that I could reach while the motor was running in the water.

 

[freddyray21]

Re: overheating

tstat. water will come out of the pee hole even before the tstat opens. Did you change the impeller as just usual maintenance or was there an issue? If the old impeller fell apart a piece of it could be clogging the lines.

 

[scully222]

Re: overheating

I changed the impeller, pump housing, gaskets, and grommets. Is thermostat hard to change?

 

[freddyray21]

Re: overheating

I changed the impeller, pump housing, gaskets, and grommets. Is thermostat hard to change?

very easy. three bolts. It should be right on top the block just behind the head.

 

[ezeke]

Re: overheating

Unfortunately, your thermostat is at the bottom of the cylinder head and you will need to remove the cylinder head. I have to remove the cover latch on mine to do that without removing the powerhead.

See LeeRoy Wisner's article: http://www.sschapterpsa.com/ramblings/water_circulation.htm

There is also a possible water circulation problem with the base where the powerhead connects. I have never corrected one, but I have heard of it a lot.