Most of my heavy duty mechanic stuff, on four strokes, was based on a 2006 crf 250f Honda. A bike that had very sketchy reliability, and went through a lot of parts. In many ways, that engine is like taking a bandsaw to a gsxs 1000 and saving one cylinder.
Honestly, the problems with this motor happened when it stopped ticking. That lack of ticking happened when the valves went to zero and it became tough to start. The thing is , this happened without a few miles and about 45 minutes. Not 800 miles.
In the old days, much of this sound could not be heard. I think you hear much more in modern times due to the thin castings and thin covers. This sucks, for the noise factor, but it also allows this bike to weigh 475lbs and not 575.