I have a 94 sc650 runs fine except somtimes when i put it into reverse then into forward again you get a lot white smoke and you rev it and it dosnt seem to go anywhere the flap that comes down to reverse the jet direction ok and seems to be returning correctly for forward position is there a flap that does the exaust to? anyone got any ideas?

 

Sounds like its cavitating. Is the ski a 2 stroke? If so the smoke is normal. As for cavitation, when the clearance of the impeller is out of spec it creates small bubbles in the jet stream "cavitation" and will stall the ski. I say get your pump checked by someone that knows how.

 

Hi yes it is a 2 stroke, the jetski goes fine in forward long as you dont touch reverse its when you go from reverse to forward again the problem starts but this is only somtimes othertimes it will be fine if it was cavitation would this happen constantly i know it did have a new impeller when i bought it so perhaps it could been fitted wrong?