The component with the lowest price in the OIL PUMP schematic is the Screw,cross 5x10.
In this schematic the "Screw,cross 5x10" is used most often.
Parts such as the Oil Pump: Pivot,oil Pump, Screw,cross 6x16, Rotor,inner, Screw,pan 6x22 are included in the Z50r 1998 (w) Usa Oil Pump parts fiche.