The most reasonably priced component used on the Gsxr750 1989 (k) (e01 E02 E15 E16 E17 E18 E21 22 24 25 34 39 53) Starter Clutch is the Pin(7x11x42).
four components are shown in this Gsxr750 1989 (k) (e01 E02 E15 E16 E17 E18 E21 22 24 25 34 39 53) Starter Clutch exploded diagram.