Sounds about right to me, at least at idle. At first it sounded a little like it was missing, but it's hard to tell if that's the bike or the recording. When everything is adjusted right (cam chain, valves, a/f and carbs synced) mine, with the stock airbox and filter, the engine on mine sounds like an angry sewing machine at full speed (ignoring the exhaust sound). The top end of my motor, for lack of a better description, makes a lot of "snick-snick-snick" sounds, and I don't hear the same in your video. Mostly all I can hear is the exhaust, which sounds pretty similar to mine.