A functioning starter is, for reasons of safety alone, vital. Being unable to re-start the craft, whilst being pushed by a spring tide or wind, or both, is, to say the least, undesirable.
The assembly is relatively simple and can be refurbished by a competent amateur mechanic, new brushes, more often than not, generally does the trick.
The major components are not prone to failure unless the engine has been standing too long outside, and therefor they may be corroded beyond practical use.
More starter related parts you may wish to consider:
Add as many components as you wish to the same shopping cart, for example new bolts 9709506012 & washers 9299008600 9299006600 to replace those that are corroded or damaged beyond use, and still only pay the same fixed price shipping cost. Professional quality Gasket Seal:08C70K0234M. This component may have other applications within the Yamaha model range. Check the part-numbers you order are correct for your application.