I Just recently purchased a 98 bass tracker with a jet pro 120.

I first ran it and it seemed to idle rough and had a little rattle noise. It ran good and still does. The problem I'm having is where the exhaust comes out of the engine get really hot and I noticed it even melted the water line hose on a 3 mile river run. The water is not cooling down the engine and Im defiantly not a mechanic. The paint actually got so hot where the exhaust and water comes out and started chipping. Any advice is appreciated

The motor was completely rebuilt and oil injection parts were taking out so I mix oil and gas now.