We where riding hard down the river for about 6 miles. He would pull slightly on me in the straight stretches but I would catch up or pass him in the tight corners. We were side by side going into a 2 mile straight stretch. He had me by about 5 sled lengths at midpoint but I was 10 feet in front of him at the end. The length of the tow rope. Blew a piston. Only about 200 miles on his sled. That's the second Ski-Doo that I've seen blow up this year. I'm not bashing Ski-doo's, just it can happen to anybody.