opened my air box today to check my air filter and found about 1/4 inch of oil in the trough next to the intake.paper and foam filter were dry.engine oil level is full.any idea what could be the cause? the bike was recently serviced. would this be a sign of them overfilling the crankcase? thanks for your help.

 

the only time ive ever seen oil in the air box is if u got stuck and the bike was tipped over or on its side for a period of time, other than that i dont know? good luck