The most expensive part in this assembly is the Cylinder 1.
The Yamaha CYLINDER HEAD has thirty-three products enlisted in the schematic.
Parts such as the Cylinder Head: Pin, Dowel, Bolt(81e), Valve Assy, Cylinder 1 are included in the Yz125 2019 B0v2 Europe 1ub0v-300e1 Cylinder Head parts fiche.