balance carb huh? okie that one simple, first you turn off your engine, get your carb tuning allen key and close the AFR screw all the way then open two rounds, maark the allen key when its full lock and turn two rounds from there, each carb do the same... then later after that tune from there, make sure the idling screw is also adjusted once the two screws had been unscrewd 2 rounds.....
then adjust from there, watch for irragular idling and also the sound of each carb intake... you can tell from there wan :D