I use Seafoam, and haven't had any issues. I also try to run my sleds once in the middle of the summer.
I talked to our local sled shop mechanic (he's been the for 15 years), he told me that he does alot of carb cleaning on customers sleds, and he always ask them what they use in thier gas. The sleds that use Seafoam always look much better than that of sleds that use stabil...