KZ440 issues

I have been restoring an 1981 KZ440LTD for some time. I have it running pretty well with plenty of power but still have a couple of issues: the bike hesitates and sputters a little between 1500 and 3000 rpm. I have cleaned the carbs and and replaced the air screws, float needles and rubber gaskets. It has new plugs and wires. I'm not certain I have the air screws set correctly does anyone have some advice for turns out, the manual recommends starting with 1.5 but when I initially removed them they were around 5 turns out, this seems like way too much. I am also experiencing excess engine vibrations, could this be a sync issue? Any advice would be greatly appreciated.

1.5 turns out is a good starting point. If they were 5 turns out, make sure there are springs install underneath; the springs provide mechanical lock for the screws so they don't back out on their own... If the carburetors are synchronized, the bike WILL shake some.