oil leak, rubber "S" hose from left Crankcase cover to OCS
 

Whew, that title is too long for such a simple little hose. Recently I found that the S shaped blowby hose going from the left crankcase cover to the OCS valve had been rubbing against the clutch cable. Finally the cable rubber through. This came to light when I started to clean my bike after a recent 1100 mile weekend. Bottom line, it's a good idea to check that clearance from time to time. The replacement part is inexpensive. This is just a messy problem that is easily fixed and probably resulted from some engine maintenance that put the two parts too close to each other. My bad.

Peter Y.