In this schematic the "Disk,friction (nas)" is used most often.
Parts such as the E-7-1 Clutch: Advancer,spark, Nut,hex.,10mm, Rod,clutch Lifter, Through,oil are included in the Xr500r 1981 (b) E-7-1 Clutch parts fiche.
The most expensive part in this assembly is the Outer Comp,clch..
