On my 2000 yamaha zuma, there is a air box on the carburetor, which has a vent hose for excess oil/ gas to escape, which i have messed with ever since the area below it has gotten saturated in 2 stroke oil. i've tried all sorts of stuff with the vent hose and no matter what i do i can never tell how oil gets from the carb through the airbox to all over the bike. Is something wrong with the carb? (the oil injector is built into the carb.) Is there a way to regulate oil to gas ratio? it may be running too rich on oil. the bike performs fine but i need to figure this out! HELP!!