TD-20 cooling question

[Daviet]

First time working with this type of engine, seems to be overheating by my temp gun. If I remove the copper tube that comes out of the bottom of the head, I seem to have water flow. It looks like exhaust is coming out of the copper tube as it comes from the exhaust housing. I am wounder if I am getting exhaust into the cooling system causing it to overheat. Any thoughts from you guys that work on these engines?
Thanks for your thoughts.

 

[Joe Reeves]

Re: TD-20 cooling question

1946-1949 5hp Johnson Model TD20

For combustion/exhaust to enter the cooling system (exhaust at the water tube), that normally requires a failing head gasket which allows the pressure to create a stalemate.... combustion/exhaust going down, water coming up, the water travels so far and can travel no further due to the pressure so it sits there and boils.