Re: over heated outboard
If you haven't disassembled this motor yet (???), and one piston is moving while the other is staying still . . . that's a very bad thing.
It means you've probably got a broken rod or crank.
Can it be fixed? Probably - could be a lot of $$ though and it will certainly need some kind of machining. If you're aiming to fix it yourself, then start taking it apart. If you want to pay someone else to do it, you're better off finding another motor.