i operate a 1989 searay sundancer with a 7.4L engine driving a mercruiser bravo one outdrive.the coupler is a mercruiser P/N861523A11.the outdrive is new this season.i have operated the boat this season for approx 20 hrs at normal speeds.recently while operating the boat at 3200 rpm and 23mph,the boat suddenly droped in speed to 9mph and the engine overreved.i proceeded to destination at 9mph and speed would not increase regardless of rpm increase.the next day i again operated the boat to repeat the problem,but the boat regained almost normal operation with a loss of approx 5mph based on prior normal operation.anyone have an idea of what is going on?
