Carburetor Mid Body Gasket Kit. The All Balls carburetor mid-body gasket kit contains all the necessary components to replace the gaskets in your carburetor. NBR rubber material is used on all O-rings and rubber gaskets - NBR has excellent resistance to the ethanol used in today's fuels. Sold as a kit. Notes: Kit contents will vary based on fitment. Models with multiple carburetors include components to repair all carburetors. Note: Keihin FCR mid body repair gasket kit.