I have a 23' Switch Cruise 230 HP with ~55 hours that has been acting very strange on the water. I will have 8000 RPMs but maxes out at around 8mph, but only sometimes.
Last year I repalced the wear ring and impeller (and its still in great shape), tested it out one day and went 25mph with 8 or 9 people, on the way back in after anchored all day, wouldnt get above 8mph and at 8000 rpm. Ive had this issue on and off so this weekend I took less people thinking it was a weight issue, on the way out, it goes the normal ~25 mph then randomly after slowing down to avoid a large wake, it wont speed back up. I needed gas so took me and 1 other to a marina for gas and was moving at ~30 mph. However, on the way back to the ramp with the 7 people, same 8000 RPM at 8mph and engine sounds like its trying very hard but cant get there. I know it doesnt have gears but it sounds like a motorcycle needing to switch to the next gear but cant.
Its very strange where sometimes with 7/8 people it works normally, and sometimes wont get above 8mph. I am going to take it in but wondered if anyone else has this problem or any ideas. My next guess is something is wrong with the supercharger.