Before you pull the valve cover to check the reed valve snug all the head bolts down do not over tighten. Also check the bolts that hold the air housing on they get loose and start pulling air through the gasket to the carb.
If it's leaking oil down around the pan you'll have to pull the gen from the TT to get to the bolts to tighten them or install a new gasket. I would check every thing I could get to before I pulled the unit.
With the rich mixture your smelling sounds like it's pulling to much air and that pulls to much fuel from the carb and will pull the oil through the breather tube. Check the easiest stuff first.
If you pull the valve cover be careful with the gasket or be ready to get a new one. One good thing it's running there hard to trouble shoot when there not running. Just take your time back away so you can kind of look at the whole unit sometimes when your right up on them you only see one spot.
