"I have twin 318's in my 7
"I have twin 318's in my 70 Jersey Flybridge which overheat at any throttle setting above idle. They run hot at idle. I have replaced all of the impellers and the heat exchanger(used, but pressure tested and visually inspected). I have also replaced the risers and elbows.
No change in the problem.
There is coolant loss to the salt water side (goes out exhaust).
Next best step is to replace head gasket? Motor was overheated hard when a friend operated boat last year. I did not replace the exhaust manifold, but it appeared to be in good condition."
"I have twin 318's in my 70 Jersey Flybridge which overheat at any throttle setting above idle. They run hot at idle. I have replaced all of the impellers and the heat exchanger(used, but pressure tested and visually inspected). I have also replaced the risers and elbows.
No change in the problem.
There is coolant loss to the salt water side (goes out exhaust).
Next best step is to replace head gasket? Motor was overheated hard when a friend operated boat last year. I did not replace the exhaust manifold, but it appeared to be in good condition."