http://www.bikebandit.com/houseofmotorcycles/1978-honda-cb550k/o/m9449#sch400930At first I thought you were talking about the "fuel rail" type piece that goes between them. (its between the number 1's which are o-rings on the drawing on bike bandit.)Now i'm thinking it's just a breather tube and on mine there wasn't ANYTHING there...but mine was a 76' Do they go to dead ends? I don't think those are necessary,hopefully someone else can chime in if they ARE indeed needed.
There is a short rubber hose that connects each carb together. What is this part?
If we're talking about what I think your talking about, it's just a bit of fuel line. Should be 5.5mm, but that's impossible to find these days so just use 3/16" (5mm)