REBUILD KIT, CARBURETOR. Full list of parts contained in the kit: float needle, needle seat o-ring, cold start enrichment feed pipe o-ring, float bowl gasket, main jet access plug o-ring, pilot fuel screw o-ring, slide guide o-ring, two felt throttle shaft seals, two stainless steel hexalobular socket throttle blade screws and instructions. All o-rings in this kit are FKM. NBR vs. FKM o-rings