I have a 1995 Yamaha 200 ProV that doesn't seem to be giving me full power. The engine is on a 20' Hewes flats boat and she usually scoots really good, but lately I have to hammer it down all the way just to get on a plane. Even then it is slow to get up. I also have to keep the throttle almost all the way open just to keep the boat on a plane. The plugs don't look that bad, I cleaned them as they are not that old. I'm going to replace the plug wires this weekend. I'm assuming that the boat is not running on all cylinders? I knowledge of outboards is limited but I have the book? Any suggestions.
