I have a 2001-ish Yamaha 4-stroke 25hp outboard. While running it... the power to the prop cuts out when i reach a certain speed... maybe 1/3 of full power? RPM's seem fine, but it is as though above a certain RPM, the power stops reach the prop. Similar to keeping your foot on the gas pedal of a car while putting the clutch in. Any help is greatly appreciated.