rotary shaft gear failure
Well, I think we all need some more info before we can tell you for sure, it looks like the oil supply to the rotary shaft starved for oil. there are two hoses one on the bottom of the oil tank, one on top of it.if you trace these back to the engine, one is below the intake/carburetor/injection pump (if it's still there) the other is under the exhaust manifold. if your oil tank is still there (I don't know what you have, some people eliminate their tank and just hook up two length's of hoses and fill them with oil) The rotary shaft runs in a "bath" that isn't fed by oil pressure, just gravity from the oil tank, and since most ski's have oil injection, the tank feeds both the injection pump and the rotary valve, if the tank is left to run dry, well, you may have starved the bearing and or gear for lubrication. hope this helps!