Reed spacers set the reeds further away from the engine to allow for better atomization of the fuel/air mixture. They do absolutely nothing for Polaris sleds, the stock position of the reeds was an acceptable distance away. I think Skidoo needed the extra separation on their motors. It is more common to run reed spacers on dirtbikes and ATVs.scumpman said:Sled looks awesome.. what does adding the reed spacers do for performance?? I've just got regular piston ported cylinders and don't know much about reeds.