I own a 1988 dt65. I believe there might be an issue with the transmission/gear box. With the motor running and the throttle in neutral position, everything is fine; However, when I engage forward gear, I hear grinding and the boats stays put. Out of the water, the prop seems to engage, but just enough to make it spin. I have inspected the ring and pinion gears. They look great.The clutch cam looks good as well. The clutch dog seems to be worn a bit. Could that be the problem? What else would cause this?