Parts such as the Carburetor: Jet, Slow Air (#60), Valve, Drain, Plate, Screw, With Washer are included in the C150trw 1998 Carburetor parts fiche.
The component with the lowest price in the CARBURETOR schematic is the Gasket, Drin Screw (nas).
On this parts fiche the Screw, Pan W/ Spring+- is the most specified component.
