The Valve is made up of components including this Valve-exhaust which is the most expensive.
Parts such as the Valve: Shim,t=2.00, Collet,retainer, Shim,t=2.30, Shim,t=3.05 are included in the Zr750c1 Zephyr 750 1991 Europe Uk Fr Ar Fg Gr It Nr Sd Sp St Valve parts fiche.
The lowest price component in this Valve parts-list fiche is the Collet,retainer.