These main jets 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 our online schematic where you can find all the items with virtual respective part numbers. This will aid you in locating the correct items for your model.
Check the schematic for your model and take better informed decision when placing your order. No company is more pro-active than us in seeking out those essential NOS spares.