The most expensive part in this assembly is the Semi-double Seat Assy.
With four applications this Bolt, Flange (4h7) is the most specified part.
Parts such as the Seat - Yz125k: Semi-double Seat Assy, Bracket, Seat, Washer, Plate(481), Pad, Seat are included in the Yz125 Offroad 1983 (d) Usa Seat - Yz125k parts fiche.