AR, I just had the cover off my TEV last night for the 1st time...halfway boogered up the 1st 2 screws getting them out and totally effed up the last one
After a cold one or two and plenty of cursing I finally got that 3rd one off so that I could see inside the TEV.
I don't know that I can help you test for a diaphram leak, but thought I would tag along on this thread for more TEV education
(BTW, when you pull it apart, should it have fuel in there, or is it just an air passageway? - The metal cup in mine had some fuel hanging out there. The backside of the post had some black, semi-greasy residue on it that I wiped off before reinstalling.)
These are MotoBuddha's pics...mine were not nearly this dirty. I am only concerned about the little bit of fuel and the black greasy debris on the post.
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1268545171/20#20(Didn't mean to hijack your thread, but you guys have been into this part of the carb, where I am a noob)