This morning I noticed a small amount of oil around the crankcase filter. Not much but never seen it before. Wondering if it's an issue that I need to look futher into or what. Runs fine, sounds the same. Changed oil about 1200 miles ago, level is good. Cleaned all filters about 2000 miles ago. However this is the original filter I put on about 20k ago when I ditched the Airbox. Any ideas?