Overhauling the valves and valve train? check the camshaft lobes for wear and/or damage, worn valve-guides can cause smoke on start up and a loss of performance? The cam-chain, tensioners and guides should be renewed as a matter of course.
Some of the more important parts that should be considered are this component and perhaps some of those listed below:
Add as many new parts to the same shopping cart as you wish, new valve stem seals 12209422005 & gasket kit 06112422T00P for example, and still only pay the same single fixed price shipping cost.
Please be aware that this component may have other applications within the Honda model range, so check the part-numbers you order are correct for your model and application.