The most reasonably priced component used on the Yz80 Competition 1974 Usa Crankshaft - Piston Yz80a/yz80b is the Washer, Spring.
With two applications this Circlip 132116340000 is the most specified part.
This schematic depicts all components used in the Yz80 Competition 1974 Usa Crankshaft - Piston Yz80a/yz80b partslist.