The most reasonably priced component used on the Gsxr1100 1988 (j) (e02 E04 E06 15 16 17 18 21 22 24 25 34 39 53) Gear Shifting is the Washer(12.5x20x1).
Parts such as the Gear Shifting: Stopper,gear Shift Cam, Shaft,gear Shift Lever, Oil Seal, Cam,gear Shift are included in the Gsxr1100 1988 (j) (e02 E04 E06 15 16 17 18 21 22 24 25 34 39 53) Gear Shifting parts fiche.
With two applications this Pin(5x8) is the most specified part.