To make sure that the oil pump is metering and delivering the correct oil to petrol ratio, a thorough and close inspection of the assembly is advisable on an annual basis.
If any of the subcomponents are corroded or degraded a simple like-for-like replacement should suffice.
If the pump itself has failed, then renewal is the only realistic way to ensure complete reliability with this critically important assembly.
Other components you may wish to consider:
Add as many items as you wish to the same shopping cart, new gaskets for example, and still only pay the same single fixed price shipping cost.
Please be aware that this component may have other applications within the Yamaha model range. So ensure the part-numbers you order are correct for your model.