I have owned this boat for a 5-6 years and it has always hesitated and/or died on throttle up. I could live with that but now when throttling up the engine dogs out and will not come up to RPM. There is a high pitched tinee sound. Shop says that they want to replace the impellor and some wiring. They also want to rebuild the carbs. Total cost around $1000. I think they are nuts with the impellor replacement. Any one here have a thoughts or comments?