Not sure if anyone has seen this but my buddies sled started smoking and burning coolant. Stopped and after looking around noticed that on the mag side one of the nuts that bolts down the cylinder was missing and another sheared the stud right off. We are thinking that one of the bolts must have backed of and then eventually stressed the other on and broke the stud. It was the 2 at the rear or carb side of the cylinder. Looks like it was caught in time as I don't see anything else damaged.