We looked at it today. It's blowing into the airbox from a breather that comes into the airbox from the bottom. Not sure where that comes from but I suspect it's the crankcase and that I have overfilled the oil. The airbox had a fair amount of fresh engine oil in the bottom of it and the little foam rubber gasket on the cover was soaked in oil. When I removed the air filter not long ago to service it, I completely cleaned out the airbox, so this is all new stuff. This is the source of the oil for sure. I did notice that when I was going all through the bike cleaning it, there was oily grit in that same area, apparently the previous owner made the same mistake I did but didn't clean up his mess. This poor thing didn't get a lot of TLC.
DK: I just got the bike not long ago and immediately changed the oil, due to near "owner vandalism" as my friend who works for Honda in the warranty department would say. The sight glass appears to be completely full, but on close examination I can see a tiny bubble a the very top.
Thanks to all who responded.