This motor is mounted on a 16ft sidewinder that we use for waterskiing. I've owned it since about 1993 and the powerhead was rebuilt about 1995. I've noticed a slow deterioration in the acceleration over the last few years. This year it has gotten to the point where it has a hard time hauling up a 200 lbs skier. It used to be able to rip a skier up in no time. If there's no skier (i.e less load) then most people would barely notice that the acceleration is poor. When hauling the skier, I find that once the boat planes (and the load therefore drops off), the motor then accelerates nicely and the boat takes off like a rocket. There is no problem with idle. There is also no problem with top end speed. Nothing has changed on the setup (no change in prop, no change in mounting position, etc.) I am thinking that it is either a timing problem (it is trying to advance before it should?) or a carburetor problem (mixture not right?). I have taken the boat to mechanics in the past, but they never seem to get it right because they can never put the boat under the full load of a skier. They always set it up to run fast at WOT, which I really don't care much about. The boat goes faster than I need for skiing - the most important thing is the hole shot (acceleration). The trouble with taking this to a mechanic is that it gets very expensive because it is hard to even reproduce the problem without putting the motor under the same load as a skier in the water. If someone could give me some tips on what to try I would greatly appreciate it.
