I had a friend go through my carbs (he builds bikes) as they were GUMMMMED after the po ran crap gas through them.  He cleaned and reassembled them, now they look good as new.  BUT... as I was installing them I noticed that there is a rubber bushing on the left carb that is torn.  It popped out as soon as I tested the choke cable.  The spring behind it popped out and is now visible.  I can try to pop the bushing back in, but the pressure from the spring pops it right back out.  

My questions are- will this spring being uncompressed cause me issues, will the torn bushing create a vacuum leak (or worse), and finally should I even bother putting the tank back on and filling the bowls, or should I immediately pull the carbs back off and get the new part before trying to run?

fix it before putting the tank on

unless you want practice removing the tank

I had to pull my carbs off today for a re-clean / re-build. I decided to pull out the choke parts and the rubber bushing that you are referring to looks like it sort of holds everything in place. The replacement part is about 3.00 bucks at bikebandit.com

It also looks pretty easy to take apart. Let me know if you want pics. I can post some later.

choke mechanism..... big fricking deal
put it back together....buy the part and have it sitting for next time you take the tank off

Choke mechanism is kept together by the 2 clip like things in the front of the thing that bend like a hair pin ...
I'll gladly sell you one for $5 and $5 mail. The 2 clips are needed, 1 is not enough .... to retain it on the crab body.
Cool.
Buddha.

I think he might be referring to the black seal for the choke cylinder. There is a raised shoulder on the shaft that sort of allows the seal to "grab" the shaft. (No pun intended.) If that whole piece has separated and the shaft and spring is now sticking out, it might be a big deal. I dunno.