220 main sounds large unless you are running bellmouths perhaps. That will only really have an effect from about 3/4 throttle though. What air filters are fitted? Otherwise sounds pretty much comparable. The difference in needle position (middle as opposed to top) is unlikely to have the effect you describe. You may have an incorrect needle so I'd start doing some more invstigation there as LAB suggests. If necessary get new pilot jets and the matching needles from a good source, they are not that expensive.