Engines back in the day didn't use to have balancer shafts.
Obviously it's going to have a dramatic effect on bearing life and, since there are no rubber engine mounts, a dramatic increase in vibrations through the handle bars. It becomes quite unbearable after a short amount of time.
I would say there are better things you could do to increase performance of the engine over removing the balancer shafter, like lightening the flywheel.
