The most reasonably priced component used on the Nt650 Hawk Gt 1988 (j) Usa California Oil Pump is the Bolt,flg.soc,6x14.
With a quantity of two pieces, the Collar,o Ring is the most used part in the OIL PUMP diagram.
Parts such as the Oil Pump: Chain,oil Pump Dr, Pump Assy,oil, Boss, Oil Filter, O-ring,14.8x2.2 are included in the Nt650 Hawk Gt 1988 (j) Usa California Oil Pump parts fiche.