These are items that do wear in time, almost imperceptibly at first, but the deterioration will get worse, with lower performance and difficult starting. If in doubt, replace them!
We can also supply the other items you may need to complete your carburettor rebuild - check both the Product Gallery for your machine, and the online schematic where you can find all the items with their respective part numbers. This will aid you in locating the correct items for your model.
These are items manufactured in Japan, and represent great quality and value!
Check the schematic for your model (where available) and take better informed decision when placing your order. Order all the items required in one hit and avoid multiple shipping costs. CMS - the company where enthusiasts tend to buy their Japanese motorcycle parts.