if i was going to buy a used sled........i would rather have 1000 hard miles in the mountains, than one day of that stuff on the sled. there is no way those sleds did not overheat. no way. i have been up in 5000-6000 feet range, on my at that time new m8 and just cause the trail (atleast 5 feet) was hard packed, and a bit icey i was overheating. had to stop and pack the tunnel with ice. that happend more than once, and i have seen it happen to a number of sleds i rode with.
in those conditions i couldn't even imagine how bad those sleds were damaged.