Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression, or race gas with a higher compression. Specifically designed for the pro, semi-pro and amateur rider. Freshens up their engine prior to a race or during mid-season. Kits do not include valve stem seals, rubber part, shims or other fiber gaskets.