A thorough inspection of the crankshaft and con-rod bearings for wear also the cylinder bore, piston and piston rings for wear or damage is highly recommended when carrying out a complete engine rebuild.
The cam-chain-guide, tensioner, valves, valve guides, valve springs and camshaft lobes all need to be in top condition and correctly set up for the engine to give its best.
More related parts you may wish to consider:
Add as many items to the same shopping cart as you wish, new cam-chain 9450002090 compression springs 9050122721 & valve stem seals M011212900, (but check before ordering?) for example, and still only pay the same single fixed price shipping cost.
Pro-workshop gasket sealant: 08C70K0234M. Making it easier to achieve a perfect seal every time.
Please be aware that this component may have other applications within the Yamaha model range.