How many hours does the machine have on it? Are the RPM's still reaching 8000? If the RPMs are reaching 8000 without an issue, I'd suspect the jet pump as an issue. You'd need to check the impeller for clearance and damage. If not at 8000, check for ignition, compression, injector issues. Also, the speedometer is crap. Use a GPS to verify with a phone or otherwise.mine is reaching around 43 MPH what are you guys seeing for top speed? new plugs/cleaned injectors/fresh fuel how accurate are the speedometers?