With a quantity of two pieces, the O-ring 7x1.7 is the most used part in the E-8 OIL-PUMP diagram.
Parts such as the E-8 Oil-pump: Plate,pump Settin, Pump Assy,oil, Bolt, Hex., 6x35, Gear,starter Idle are included in the Xr500 1979 (z) Canada E-8 Oil-pump parts fiche.
The Screw,cross,5x12 is the cheapest item from this partsfiche.