Stolen from the Hitchcocks forum for your delectation
'I have a friend with a 2005 Bullet. It has a 34mm Mikuni, free flow muffler, 535 alloy barrel and high compression piston. It runs very well and the carby set up is as follows: Main 190, pilot 42.5, slide 2.5, needle jet 159Q2, needle 6DH2 and clip in middle slot. The plug always looks rich to me but he is happy with it. My Mikuni is as follows: Main 200, pilot 25, slide 3, needle jet Q6, needle 6DP17 and clip in second leanest slot. I only have the standard exhaust with the cat?? thingo removed from the engine pipe (muffler end). The bike revs out better and has more top speed but still feels a bit lumpy down low and I use more fuel than I did. It could no doubt be better tuned but there are so many combinations of jets etc. I think a dyno and endless time would be needed and I'm not getting any younger. Not sure if any of this helps but at least I can sympathize with you. My carby has been on and off so many times I only have to say, "Carby off" and next thing it's on the bench by itself..'
and this
'Friends say they are brilliant carbs, but a swine to get set up correctly in the first place!! So, so true.'