Obviously you need a Carb balancer.I use the superb Carbtune2,
http://www.carbtune.com/
I made an auxiliary fuel tank with a small screw in the bottom that can be removed to allow for the vacuum created and to make it seal a small patch of old inner tube rubber that it screw through that I super-glued in place.
The pipes need restrictors in them in them(Supplied with the Carbtune2) as the Vacuum created at the carbs is too large to be useful and accurate without them.
Also supplied are the adaptors required to go into the bleed-off points on the carb inlets.
With apparatus setup and with the bike at a maximum of high idle e.g 1100 rpm + 10% max release the 8mm locking nut on the balance adjuster and adjust until the two levels in whatever device you use are level.You don't have to worry about numbers just that they are level.
The Trick:
To allow for the tightening of lock-nut taking the balance out set the balance ever so slightly out and then use the tension of tightening the lock nut to bring them perfectly level.When level and tightened lock the nut in place by degreasing with some carb/brake cleaner and some tissue on a screwdriver and apply some thread-lock.
Note:some people get frustrated when balancing the carbs and hold the throttle at higher revs and seeing the balancer level out and wrongly assume they have balanced their carbs for higher revs.This is incorrect as the vacuum created above 2,000 revs nullifies the balancer making it useless.
This can also lead to premature engine wear/failure as it may cause uneven stress on the crank-shaft over time and possibly uneven heat cycles in the heads a symptom of which may be blowing heads gaskets under long sustained riding.
All carburettor manufactures recommend balancing at the bike/engines idle speed as per above
Source: John(Sean) Morgan manufacturer of the World renowned CarbTune 2.
http://www.carbtune.co.uk/carbcust5.html
http://www.youtube.com/watch?v=xcu3veeQolo
http://www.carbtune.com/
I made an auxiliary fuel tank with a small screw in the bottom that can be removed to allow for the vacuum created and to make it seal a small patch of old inner tube rubber that it screw through that I super-glued in place.

The pipes need restrictors in them in them(Supplied with the Carbtune2) as the Vacuum created at the carbs is too large to be useful and accurate without them.
Also supplied are the adaptors required to go into the bleed-off points on the carb inlets.
With apparatus setup and with the bike at a maximum of high idle e.g 1100 rpm + 10% max release the 8mm locking nut on the balance adjuster and adjust until the two levels in whatever device you use are level.You don't have to worry about numbers just that they are level.
The Trick:
To allow for the tightening of lock-nut taking the balance out set the balance ever so slightly out and then use the tension of tightening the lock nut to bring them perfectly level.When level and tightened lock the nut in place by degreasing with some carb/brake cleaner and some tissue on a screwdriver and apply some thread-lock.
Note:some people get frustrated when balancing the carbs and hold the throttle at higher revs and seeing the balancer level out and wrongly assume they have balanced their carbs for higher revs.This is incorrect as the vacuum created above 2,000 revs nullifies the balancer making it useless.
This can also lead to premature engine wear/failure as it may cause uneven stress on the crank-shaft over time and possibly uneven heat cycles in the heads a symptom of which may be blowing heads gaskets under long sustained riding.
All carburettor manufactures recommend balancing at the bike/engines idle speed as per above
Source: John(Sean) Morgan manufacturer of the World renowned CarbTune 2.
http://www.carbtune.co.uk/carbcust5.html
http://www.youtube.com/watch?v=xcu3veeQolo