Parts such as the Crankcase Cover- Water Pump: O Ring,cl Cover Outer, Cover,clutch, Circlip,10mm, Impeller,water Pump are included in the Rm250 1999 (x) Crankcase Cover- Water Pump parts fiche.
In this schematic the "Screw" is used most often.
The sub assemblies and components that make up this Crankcase Cover- Water Pump include this Cover,clutch, the most expensive part.