Parts such as the Carburetor: Pipe 1, Washer, Plate, Cap, Plunger, Screw, Bind (5y1) are included in the Xg250 2005 4d62 Holland 1d4d6-351f1 Carburetor parts fiche.
The thirty-nine Xg250 2005 4d62 Holland 1d4d6-351f1 Carburetor component parts are all listed in this schematic.
On this parts fiche the Screw is the most specified component.