persistent and odd fuel ration

1978 kz1000a. carbs are rebuilt and clean. coils are brand new dynatech and points were replaced with electronic ignition. spark plug wires are brand new. choke plungers are rebuilt. Brand new fuel lines, spark plugs and pingle dual outlet petcock. I’m not trying to make a carb into a fuel injection system. The bike audibly stumbles at the same time as the afr bumps. i dont know which one is cause and which one is effect.

Cylinder# 2 has intermittent pockets of lien afr. cylinder 1 seems to have the same thing just to a lesser degree. these curves are all at idle (1000 rpm) I dont know the answer. It goes away if i idle the bike at about 1200 rpm. The bike is warmed up but it does it worse before it warms up. i dont think there are intake or exhaust leaks. it has been synchronized. Green is 12 afr and red is anything above 14.7 for context.

this puzzle probably doesnt have anything to do with the jetting and I really prefer not to go off on tangents but here is how its tuned.

dec 20 (rebuilt choke plungers)everything seems to go lean on throttle snap#1-(10),(100)(clip2)(3mm)small afr pops with same frequency as #2 just much smaller. otherwise afr is good.#2-(12.5),(102.5)(clip3)(3mm)large afr swings almost like a backfire but its in range#3-(10),(105)(clip4)(3mm)perfect idle#4-(10),(105)(clip4)(3mm)idle is too rich and pilot screw is almost closed