The most reasonably priced component used on the Kaf620-k8f Mule3010 2008 Usa / Trans 4x4 Crankshaft/piston(s) is the Pin-dowel,4x8.
In this schematic the "Circlip-piston Pin" is used most often.
Parts such as the Crankshaft/piston(s): Rod-assy-connecting, Pin-piston, Gear-spur, Crankshaft-assy are included in the Kaf620-k8f Mule3010 2008 Usa / Trans 4x4 Crankshaft/piston(s) parts fiche.