diaphragm

Hi all, I understand this is likely a newbie question but I can't seem to track down a definitive answer. I'm in the middle of a carburetor rebuild, and after putting the diaphragm assembly back together I noticed that it moves easily, but doesn't move back to the "idle" position on its own...

So I opened up my Carbs today, and surprisingly everything was really clean! (Good for me). So I was trying to put back the carbs together and I ran into a problem at the end where the diaphragm goes in. When I put the whole set up in the diaphragm doesnt go all the way in, so if I try to make...

I was inspecting my carbs and I saw that the rubber diagrams have basically shrunk down to a paper thin level and sealed to my carb. This is most likely due to old age (36 yr old bike) My questions is is that a cause for concern? Should I ever bother fixing it? Do you guys have any...

Is there different versions of petcocks used on our bikes? Perhaps some that will require different diaphragms? I bought a petcock repair kit from Parts-n-more but the diaphragm with those little holes in the corner that didn't line up, and the O-ring that goes on around the toggle wasn't fitting.