I have a 86 fourwinns 190 with 4.3L. It runs great on muffs but once I get it in the water I have issues. On the water when I first open her up all seems well but just before I plane out it dies. From there I have to pump the throttle to get it to start and can't hardly get above idle speed. I do have old gas in the tank mixed with new and treated with sea foam, I also changed the fuel filter. It just baffles me how it can run so good on the muffs but not on open water. Any help would be great.