The Oil Pump is made up of components including this Pump Assembly,oil which is the most expensive.
Parts such as the Oil Pump: O Ring(d:3.7,id:21.7), Pin, O Ring,oil Pump, Gear,oil Pump Driven are included in the Gsxr750 1986 (g) (e01 E02 E04 E15 16 17 18 21 22 24 25 34 39 53) Oil Pump parts fiche.
On this parts fiche the O-ring is the most specified component.