Our snow scoot would do the same thing, ended up being throttle position sensor. It would stall unless choke was on, and you couldn't start it unless the throttle was cracked open.
Does the Sno scoot have tors? I was looking at our carb and wondering the same thing. There's a sensor on the throttle and the shifting pivot on the flipper. I have yet to order the owners manual so I'm waiting to see where I can come up with one.