Reply To: Mercury Mark 55E

[billw]

I guess if I were you, I would try to duplicate the condition with the boat on a trailer in the back yard, with the motor running in a barrel. You should be able to tell if it is at least pumping water adequately at idle speed, this way. Also try pumping the fuel line primer bulb gently and see if either carb overflows. My bet is that if it’s not overheating, then it is a fuel issue of some sort. But that’s just an educated guess, sitting at my computer. If you plan to dive into this motor, the factory manual is going to be a basic requirement. If the guy before you worked on it without a manual, well, there’s is your problem….

Long live American manufacturing!