Parts such as the E-12: B/brg Rad N/com, Key,woodruff,4mm., Ring Set,piston(0, Pin,piston are included in the Crf70f 2005 (5) Japan De02-180 E-12 parts fiche.
The Clip, Piston Pin is the cheapest item from this partsfiche.
In this schematic the "Clip, Piston Pin" is used most often.