The Bolt is the cheapest item from this partsfiche.
The fourteen Gsx600fu2 1990 (l) Germany (e22) Steering Stem component parts are all listed in this schematic.
Parts such as the Steering Stem: Dust Seal,steering,upper, Seal,steering Upr Dust, Bolt, Stem,steering are included in the Gsx600fu2 1990 (l) Germany (e22) Steering Stem parts fiche.