I attempted to fix this tiny tube by soldering, but the tube is so tiny it acts as a capillary tube and sucks the solder too far into the copper tube and seals it completely.
My solution was to drill out the copper tube with a micro drill bit of the correct size to fit a very short section of non-surgical needle; which was a 23 gauge needle, into the drilled hole and bond it in with fuel tank sealer, since it has to be gas proof. My preliminary test shows this needle is well bonded, so I am pretty certain this will work long term.
I came up with the 23 gauge to come close to the size of the nozzle in second carb which was working fine. From what I read, both accelerator nozzles should be delivering equal amounts of fuel to both cylinders.