I realize I'm in a bit different world, but running hot has been a very common problem for us flatlanders. There have been 2 things that have really helped me: First is a fuel controller and a good map. That solved probably 60% of my problems. So, if you don't have one, consider it seriously. Second is to add cooling capacity to the sled. Probably the easiest thing to do is an additional tunnel cooler. As long as you're keeping a thermostat in the motor, I don't think there is any such thing as "too big". I agree with the idea of the longer snowflap as well. The cooling system in these sleds is barely adequate and the motors tend to run warm. The other thing I tend to do keep my motor under as much load as I can (aggressive clutching). I don't think the CFI system in general is able to cope well with relatively high engine RPM/low engine load situations. I think that combination can make F/A ratios inconsistant and very lean. I realize there is only so much one can do based on snow conditions, concerns over belt heat, etc. but it's something to keep in mind.