Boxerworks.com

I didn't find the post from someone who was going to rebuild their Bings but I DID recall something that happened to me recently concerning the rebuild kits!
The O-rings in the kit for the idle jet screw and the idle MIXTURE screw were the same size. The idle MIXTURE screw needs a bigger O-ring as it leaked badly.
I had to get a couple from the local Auto Parts store (Advance). 4mm x 8mm worked fine.
(Note. This is a Fat little O-ring!!)

I have used O rings from a common metric kit, that you can buy over the counter at most autoparts stores, on my CVs is the past. The universal kit cost about as much as the 8 normally needed O-rings from Bing, and you have enough left over to start your own little O ring store.