It could be something as simple as your airbox containing alot of oil that got "spit back" through the throttle body. Are you usually on and off the throttle alot? Worse case scenario is you have a leaking line to your right side intake. or the supply line is leaking by the oil pump.
2011 Arctic Cat CFR 800, Boondocker Control box, 1.5" Roetin Hornets, D&D Clutch kit, Set up for Stock Class drag racing.
1989 Ski-Doo Formula MX
1987 Yamaha Banshee, D&D Cool head, Toomey T5s, Drag porting in "Stock" cylinders.
"If its fast and drinks gas, Like it!!"