On this parts fiche the Nut,flanged,8mm is the most specified component.
A sample from the products for the Crankshaft include: Bushing,crank Pin,bro, Bushing,crank #2, Crankshaft-comp, Bushing,crank,#1.
The most reasonably priced component used on the Zr900ckfb Z900rs 2019 Europe,middle East,africa,uk Crankshaft is the Nut,flanged,8mm.