Where to find oil drain plug size?

[Mrs. Colleen]

I need to know the thread size and pitch for the oil drain plug on my bike but I cannot find the info anywhere. I want to eventually put on a plug that is pre drilled for safety wire. Mark asked the guys at the bike shop to look it up in the catalogs but there are no pre drilled ones made specifically for my bike. I need to find the size so I can find out if there is another bike's that would fit.

...unless anyone knows if the bike shop would be able to drill it for me?