[squirrel_hunter]

Its never easy to diagnose an engine fault from a video clip over the internet, but I've heard SV engines like that before and its not been a good outcome. However to be sure you will have to strip the engine down. But lets not get ahead of ourselves, have you checked that the exhaust headers are secure with no leaks? How about the spark plugs? It could be a simple fix, or it might not.

With regards to the ball bearing if it was from outside the engine it could be totally unrelated. If it came from the clutch worm that should be easy to find as its a simple mechanism to disassemble and check. If it is from within the engine it will basically just be from the gearbox as the main crank uses plain bearings and the sprag clutch "bearings" are not round. If one of the transmission bearings had failed I would expect to find play in the input or output shafts (wiggle the clutch and the front sprocket). Though if you had an issue there I wouldn't expect it to cause an engine noise like that, but you never know.