Water-pumps, on Japanese made engines at least, are durable and reliable - unless - the wrong coolant is used over the longer term, by wrong, we mean tap water!
The lime deposits in the majority of domestically supplied tap water play havoc with the internals of the water-pump, and indeed other areas of the cooling system. Anyway, if the pump requires attention because of incorrect coolant or just a high mileage with normal wear parameters, then this component and perhaps some of those listed below maybe required:
Add as many water-pump related components(or anything else you fancy for that matter) as you wish to the same shopping cart, new circlips 9900910400 seals 931011009011H1243800 and O-rings 93211113A8 for example, and still only pay the same single fixed price shipping cost.
This part may have other applications within the Yamaha model range.