Moved this posting to a more appropriate location.
Yes, it is common on the DOHC bikes to have a bit of oil in the
left side crankcase cover. This houses the pickups for the electronic ignition, and the gears for the starter. If it's on the side stand, oil will definitely come out that side. Best to put the bike on its centerstand or a jack if you want to pull that cover.
If it's REALLY the
right side cover, there may be a bit of oil in that cover, but not too much. If there is a lot, then there may be a oil seal issue on that side.
Others with more intimate knowledge will chime in shortly.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.