This sled falls on it's face and back fires just off idle when cold.When it warms up it only has a slight hesitation that's hardly noticable.I've cleaned the carbs (has smart carbs) and put fresh gas in it(sat for a year).Any help would be appreciated.Thanks,Ken

Well, my old sled was being stupid too and found ice to be inside the fuel pump restricting the diaphram's movement. Just something to check out. Also blow your fuel filters out.