Of all the components used in this assembly the Pump-assy-oil is the most expensive.
Parts such as the Oil Pump: Tube,3x6x380, Nut,6mm, '0'ring, Clamp are included in the Jf650-a5 Jetskix2 1990 Usa Oil Pump parts fiche.
This OIL PUMP assembly utilises two Nut,6mm(s) - the highest specified component.