Just finished some top end work on my '83 ST, and I am puzzled as to why I can't seem to stop the oil leaking from my left side valve cover. I had removed the old gasket, which was pretty well cemented onto the head, cleaned the residue off the head, and installed a clean, dry new gasket. (I elected to leave the old gasket on the right side after seeing how difficult it was to get the old one off the left side. Naturally that side isn't leaking.) Valve cover center nut torqued to spec. Ran the bike in the garage a couple of times with no leaks while running; however, a pretty fast oil drip began from the bottom of the left valve cover shortly after I killed the engine. Decided to try again with another new gasket (the one I had intended to use on the right side), and took the bike for a good long ride to get the head up to temperature. Again, no leak while running, but almost instant oil drip when stopped. No doubt there is something I am overlooking here. Any ideas, airhead gurus?