'99 GP800 issue after carb and cylinder rebuild
1999 GP800 in good condition. Bought it last fall, had new power valves and Waveater clips installed, new pistons installed and the carb was rebuilt. New fuel, new fuel selector knob (on, off, res), new fuel filter. I use pre-mix.
I ran the ski today. Started right up, but there is a problem. Moves fine at low rpms, but tops out at 4500 rpm. I spent 45 mins or so driving around the harbor. If I had enough room and held the throttle at a half twist, I could get up to 20 mph and then it would gradually gain speed. Periodically, it would launch into full throttle mode, but the water was choppy and I couldn't hold this for long. Meanwhile when the ski is maxing out at 4500 rpm, there is constant surging of the engine, as if it's getting spurts of fuel. When on the trailer, the engine runs properly, with no maxing at 4500, so the problem seems to be under load.
The reeds were not inspected or replaced during the engine work at the dealer. The service guy tells me the reeds are not likely to be the culprits here. He thinks maybe the problem is with the impeller, maybe too much gap between the impeller and the sealer ring. I bought a feeler gauge and will inspect this in a couple of days.
Any thoughts or suggestions?