25 hp Johnson - exhaust housing temp?

[P239]

How hot should the exterior surface of the exhaust housing (middle area away from the exaust ports) on my 1982 Johnson 25 hp get after idleing in a test tank for 5-10 minutes? It gets relatively hot to the touch (can hold my hand on it, but not for very long). The impeller is good, strong pee-stream, pee water is only luke warm even after long hours on the water. I'm curious, because the exhaust housing runs much warmer than my 2000 Johnson 15 hp where I can keep my hand on the exhaust housing for a long while. Is there any rule of thumb regarding temp of the exhaust housing on this engine or is it variable? Just want to make sure this old 25 hp is ok.
Thanks, P239

 

[jethro66]

Re: 25 hp Johnson - exhaust housing temp?

my 1972 25 hp is hot as well could be the thermastat?Wat do U think Guys?

 

[DJ]

Re: 25 hp Johnson - exhaust housing temp?

They all get hot. As long as the cylinder head doesn't get too hot, you have no issues.

 

[P239]

Re: 25 hp Johnson - exhaust housing temp?

They all get hot. As long as the cylinder head doesn't get too hot, you have no issues.

Thanks on that info. -- glad it is nothing to worry about. The flat part of the cyl. head gets to a warm temp. where you can hold your hand there for a few seconds or more, but not what I would call hot.
Appreciate the assistance. P239