Parts such as the Crankshaft/piston(s): Pin-piston, Gear-spur, Ring-set-piston,std, Rod-assy-connecting are included in the Kaf620-sbf Mule4010 2011 Usa / Trans4x4 Crankshaft/piston(s) parts fiche.
On this parts fiche the Circlip-piston Pin is the most specified component.
The Crankshaft/piston(s) assembly is constructed from several parts from which the Crankshaft-assy is the most expensive.