Parts such as the Oil Pump: Pin(5x18), O Ring,oil Pump, Gear,oil Pump Driven(nt:37), O Ring(d:3.2,id:17.8) are included in the Gsx600fu 1999 (x) Oil Pump parts fiche.
The Pin is the lowest priced item on this Oil Pump schematic.
The Gsx600fu 1999 (x) Oil Pump consists of fifteen pieces with the Pump Assy,oil being the most expensive.