[The Cajun]

Don't know if you have any around where you live, but oilfield supply stores have any type you need.
I know True Value handles the brass ones, but I prefer the stainless for just a few bucks more.

[steve86]

It is threaded right into the tank? I forget if the petcock has two mounting bolts like a motorcycle or threads in. Have to look at a diagram (generator isn’t here at my house).