2000 Yamaha R6 with oil in airbox?

[kumpy]

Got a track bike only 2000 Yamaha R6 which is carburated. Recently took out the airfilter to clean. Noticed a film of oil around the bottom of the airbox near the air funnel. Is this normal? It is dark brown and looks very much like engine oil, not oiling from the K&N filter. There is about layer of oil surrounding the air funnel are inside the bottom of the airbox. Doesn't look like a lot, but I'm not sure if it should even be there? The oil is moderate and minor and is isolated specifically around the air funnels leading into the carbs. Currently, the R6 has been running fine and is a good running bike so I'm assuming this is ok because if there was something majorly wrong, I would notice it very quickly on the track. I hear carbs run "dirty" and so this could be normal?

[G21forme]

Perfectly normal.

[DaveZX6r]

Bikes have PCV, positive crank vent, just like a car. When the crank case gets pressurized it cents thru a tube into the air box and sometimes caries oil mist with it. If you've ever pulled the intake manifold off a car you would see the same thing. Just wipe it up from time to time. If it starts getting excessive check your compression because your rings maybe on there way out but otherwise ignore it.