Sunday during a day out the motor didnot miss a beat, however after running 2 hrs, the motor seemed to have a slippage in the prop. This was very brief, but about a minute later the prop stopped turning alltogether. The motor runs great, but the prop will not engage in forward or reverse even while flushing the motor on the driveway. I didnot hear anything break so to speak. Does this sound like a spun hub?