I have been having an issue where I can open the throttle wide open, it will rev to around 4000 rpm, then backs down to idle rpm, even with the throttle open. when I let off the throttle there is no change. Still at idle rpm. after a 4 or 5 times of this, letting off the throttle will cause the jetski to stall. Once I start the jetski back up, it repeats the same issue and stalls after the 4 or 5th time. It sounded rough when this started happening, and I changed the plugs thinking that it might be a bad plug or two. After changing the plugs, I am still having the same issues. Anyone have any ideas?