Well, after consulting my friend "google" I learned that the problem could be that the little teflon washer may have gone missing. After disassembling the airbrush head (where said washer should be located), I realized - yup, no teflon washer.
|It's part #50-055 in the diagram above
Of course, once these arrived, I actually found the missing washer on the floor of my layout room. I kid you not. Ah well, now that I have so many extras, I doubt I'll ever lose another one!
So, if your Badger airbrush is sputtering along and not working right - check the head for that little piece of white plastic. And if it's missing and you can't find it, let me know. I may be able to help you out. :^)