I guess its a 08 polaris 120, it fouls plugs like no tomorrow, fouled one in +30 weather, another at about -10 and another around -20. They last for a few days and then come out black as heck, and it leaves little black circles from the exhaust in the snow, have'nt had time to try to figure it out until now, on these sleds, the one screw that I see is adjustable is the air screw correct? or is it a fuel screw? It has been like this since we got it. Been through maybe 6 plugs in a month. Starts up and idles fine with a new plug, so I dont think the oil ring is leaking, it isnt more then a month old.