Ahhhh....my favorite....let me guess, you also have tell-tale dual oil puddles on the floor?
It's most probably oil-pressure sensor, located behind airbox. It's sealed with plastic and usualy leaking over clutch-case. It's common and cheap problem (if you recoginize it
Sensor costs 10$ in the shop.
When you're done with that, check out return-tubes, then valve-gaskets (in that order).
Cheers!