I have a 1999 770 and when I turn it on and give it a little gas it rev's up real high and won't go back down even after I let off the throttle. What really stumps me is when I hit the off button on the handlebar it doesn't shut it off, I have to turn the gas off for it to shut off. Here is what I have done since I have owned it. I rebuilt the engine, new crankcase, new pistons and rings, had the cylinder walls bored professionally, new exhaust hoses, switched over to premix and zip-tied the oil pump up because I didn't want to take the throttle cable off of it. I have checked all the throttle cables to make sure that they aren't kinked or anything but I don't know what else to check. Any solutions or things for me to check or do would be appreciated a lot because no one around me works on tigersharks anymore.