Replaced my air cleaner today and spotted a puddle of oil in the bottom of the housing. It looked like fairly new oil, and it's only about a teaspoonful. Does anybody have any idea what this is all about. Is it something I should be worried about. I've got 4300 miles on the bike, 3300 since the thousand mile service, and this oil looks almost brand-new. The old air filter wasn't all that dirty and I didn't see any oil on the filter. Anybody have any ideas?