Parts such as the Turn Signals (km100-a1-a4): Washer-plain,12mm, Nut,12mm, Bolt-upset, Nut,6mm are included in the Km100-a7 Km100 1981 Usa Canada / Mph Kph Turn Signals (km100-a1-a4) parts fiche.
The lowest price component in this Turn Signals (km100-a1-a4) parts-list fiche is the Washer-plain,6mm.
With eight applications this Screw-pan Head,4x20 is the most specified part.
