rebuild engine on 1998 Yamaha waverunner GP 1200 INstalled new stator and CDI and still machine dies out at top speed if you let go of throttle will stay running then you can go again if you also hold it at 5500 RPM it will drive all day like that but at anything over 6500 RPM dies out and will stall if you hold the throttle open. Does anyone know why?