I have a 115 HP Mercury and it falls somewhere between 1974-1978 and I can find out for sure if the exact year is needed. It is a 6 cyl 2 stroke and I am having some running problems. When I first got this engine 3 years ago I hooked it up to water and it ran great. No knocks or ticks. As soon as we put it in the water and put it under a load it would start to die unless I kept pumping fuel to the engine using the primer bulb. I shut the engine off and took the cover off and engaged the throttle and I noticed that the carbs were not opening to their full potential. My question is do I have a fuel problem, a carb problem, or both. I know the timing advances with more throttle and I was wondering since the carbs were not opening all the way was the engine starving for fuel or is the pump to weak to give it the necessary fuel? Any leads or ideas would be great.
