'07 600 RMK scored cylinder - need advice

We took off this morning, it was 3 deg. F. The RMK died a mile from the truck. It started back up and we took off again. It died two more times and on the last time it was locked up.

Tore it down and found the PTO cylinder and piston are scored. The crank and rod bearing look good.

The tops of both pistons looked the same, the mag piston had some wash on it, but the PTO piston had no signs of any wash. The inside of the ex. manifold had a light chocolate color.

I am wondering if a PTO seal could be bad or if the carb may have iced up and plug a jet up. My son said it was kind of boggy before it died each time. The machine has 2200 miles. Been a good running sled until today.

Thanks

RMK

I'm going to check them out today, thanks.

carb boot

I pulled the boot out and didn't really find a spot where air could have been pulled in. The rubber has loosened up from the metal ring in a few places, but there is no path for air to get in.

Would this be the delamination thing that causes problems?

Thanks

No, we have been riding it a lot this year. I didn't see any water droplets in the bowls or the slides, they were really clean.

A friend of mine told me it may have been moisture in the fuel. We have been having warm days and then really cold days lately.They are in a trailer and it warms up nicely during the day. I haven't put any Iso-heat in any of them since the beginning of the season.

Thanks