Some items from this specific schematic: Clip,pison,pin, Roller,3x15.8, Gear A,sub, Piston (std).
The Crankshaft/piston assembly is constructed from several parts from which the Crankshaft Comp. is the most expensive.
The most reasonably priced component used on the Mtx125rw 1985 (f) Finland Crankshaft/piston is the Wash Wave 12mm.