Was out fishing all day out around City Island, NYC. On the way home I need to get some gas. I went to a fuel dock on the NJ side of the Hudson river. After getting gas I put the boat in reverse and all I heard was BANG BANG BANG. Sounded like the whole lower unit blew up. The The gas guy pushed me back and I put it in forward, no problems, no noise. I decided to head up the river to marina. The boat ran fine all the way up. Now this got me thinking, there is only one shaft and if something breaks for reversed I should have problems in forward too. Hmmmm.. Well i got back to my marina and pulled the cowling, I was thinking maybe the cable is not putting it all the way into gear. That all look fine. I tilted the motor up and was just kinda looking at the prop and I reached down to spin when I noticed a shinny spot on the zinc. I grabbed that and low and behold it was very loose and hanging low. When the mooter went into reverse it turned the opposite way from how it should be and was getting whacked by the prop. Luckily I took advise from you guy's here and had a tool bag on the boat. all is good and a lesson was learned.