Professional engine builders replace inlet and exhaust valves, springs inner and outer, valve guides, retaining cotters, seats, tappets and retainers as a matter of course when carrying out a cylinder-head overhaul.
The valves and the interfacing components have a tough time and can become brittle with age and wear; broken bits of metal are not too good for the engine!
If the cylinder-head is to be removed and refitted, ensure new bolts are used when torqueing down, the old bolts will have stretched thus giving false torque readings.
Also the valve train itself requires close examination, the condition of the camshaft lobes, cam-chain, tensioner and guide should all be considered when overhauling the top-end.
Other cylinder-head and valve train related components you may wish to renew at the same time as this part:
Don't forget to order all the new gaskets, seals and gasket sealant 08C70K0234M you will require. Add as many items as you wish to the same shopping cart and still only pay the same single fixed price shipping cost. This component may have other, sometimes unrelated applications, within the Kawasaki model range, so please always check by the part-number rather than the description prior to ordering.