I was out cruising in my boat yesterday all day. late at night we floated back to the dock. started fine the few times I had to reposition the boat in the channel but when we got near the dock, it suddenly would turn over and run for only a split second. this was a brand new crate motor 3 years ago and I have never had a day of trouble. only thing changed recently was that I put an Amplifier and subwoofer in the boat yesterday. anyone have any ideas.