There's a 1/4-turn plug at the left rear underside of the air box on my '03 1150R. It has an O-ring seal on it. I noticed today that it appears to be leaking oil, actually found a small drop on the ground in the garage. I removed the plug and cleaned it off, but you really can't get a good look into the hole it plugs. I removed the air filter and, while it is 10K old and needs replaced, it wasn't totally clogged or anything. The bike has been running fine, no smoke on start-up or unusual oil consumption. I did just return from a 1200-mile weekend.
Why would there be oil in my airbox? Should I be concerned? The bike has 19,700 miles on it and was just dealer-serviced for the 18,000-mile tune-up a few weeks ago.