Motors with counterbalancers tend to have cranks that are not very well balanced. Because of the balancer, they don't need to be. Saves the factory a lot of time in finishing off the crank. We have seen this with Hayabusas and Blackbirds.
Removing the balancer without having the crank balanced to a tight tolerance may result in unpleasent vibration. Maybe someone who has done this can comment.
About half of the cranks we get in for our lightening and race balancing service, the customer request that we remove the balancer drive gear.
To see one of our busa cranks, go to aperaceparts.com, click on new products and scroll down. That one still has the gear.
Jay