If this is on the bike in your sig, then yes, there is an oil seal in the very back. It takes all of about 30 seconds to take all that timing advance stuff off, and 2 8mm bolts on the side take the plate off, where the oil seal is. Im not sure if you can still get these from a Honda dealer or not still (you should be able to), but if not you can get a full oil seal set aftermarket.
Edit: There is also a large o-ring on the back of the same cover the seal is in, which might also be the cause of the leak.
-Nick
1988 Chevy Silverado 5.9L Cummins : 1986 ATC250R : 2012 Polaris RZR 570 :
98% of Americans say 'OH $#!T!!' before going into a ditch on an icy road. The other 2% are Alaskans, and they say 'Here, hold my beer and watch this!!'