The counter balance shaft is there to deaden vibration, being that the engine was orginally for a sit down ski. The crank will be fine without it. A unbalanced crank is a unbalanced crank. It will eat bearings with or without a balance shaft. Make sense? All the weight reduction on the rotating assembly should really make this engine weapon. It was already a powerhouse! So im excited to see what this does! Not to mention the amount of weight its shaved off of my ski. Ive shaved about 30 pounds off of the engine. And about 15 off of the ski!!