took my oil plug into a local auto supply store and described that a couple of the threads in the aluminum case had come out with the plug and asked what they recommended as a fix. I figured I'd have to drill and re-tap another hole. Well, they took the stock oil plug, which they determined to be a 12mm plug with a 1.25 pitch. They sold me a 12mm plug with a 1.75 pitch, which was self-tapping. I went home and started to thread it into the hole using a 3/8" ratchet and a socket. Every turn or so I would back the plug out and wipe all of the metal shavings away. A couple of minutes later the plug seated and the job was done. The plug came with a gasket, which I used, whereas my stock plug never had a gasket. I filled the old BUBF up with oil and fired her up...no leaks! This fix worked for a BUBF, but I'm not sure of the stock sizes of the plugs on other Vulcans. The plug was made by Oil-Tite, part number 65213, and was a 12mm with a 1.75 pitch (M12-1.75). Cost was $2.99; repair time was about 5 minutes.
An additional tip from Michael (Puttalong) Baum: Use "thread cutting oil" during this process for a more effective and neater job. You'll find "thread cutting oil" at any hardware store. Look for the type specially made for cutting threads in Aluminum and other non ferrous metals. About $3 for a can.
Thanks to Uturn VROC 1125