BSA 650 A65 500 A50 Oil Line Manifold X-ring SET Lightning Carb Jetting this part (0420-49-120) is the

this part (0420-49-120) is the crankcase vent spigot used on just about ALL Ducati singles

This kit is NOT suitable for chronometric instruments

A set specifically for MK3 primary cases

Standard size

NOS catalog of Norton motorcycles

BSA 650 A65 500 A50 Oil Line Manifold X-ring SET Lightning Carb Jetting this part (0420-49-120) is theShould be suitable for ALL unit 500 and 650 BSA, oem part # 68 0588. X rings to replace the nearly always leaky o rings BSA used at the oil pipe junction under the engine. Doubling the surface sealing area, the rings work really well. An alternate size also available for most singles, check the store.