Nut

A functioning starter is, for reasons of safety alone, vital. Being unable to re-start the craft, when 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:

6N78180000
6N7WS81801
6N78185000
6N78185010
61A8180900
61A8182400
6N78181000
6K78182G10
6N78184000
6N78180100
6N78181300
6N78182000
61H8180700
61H8185700
6N78183000
6K78182610
6E58182E10
6E58182F10
6E58182K10
6K7818220094
9011908M76
9011908M77
9709508016
9708008016

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.