The heart of the engine relies on the piston fitting to precise tolerances, no little end movement, and piston rings sealing correctly. Equally important is that the big-end and crankshaft main bearings are showing zero play. If all the above points are addressed, then the engine will give its best, especially if the cylinder -head and valve train has been overhauled.
Other crank and piston related components you may wish to consider:
Add as many items as you wish to the same shopping cart, new circlips 9345024028 for example, and still only pay the same single fixed price shipping cost.
This component may have other applications within the Yamaha model range, so please make sure you order the correct part number for your application.