Just bought this bike, it's in very good nick, 100% original, about 40k miles.
I noticed when the engine is hot (afer about 15 mins of riding) it starts making a knocking sound from the top of the engine (at idle only). Also between 4-5000tpm between half and full throttle I can clearly hear the camshafts working. (like a strong growl, don't know if that's normal or not.)
I've looked all over the internet but can't really find anything that explains my situation properly, it could be the cams, pistons or even exhaust gasket leaks.
Here is a video I made of the noise:
Thanks in advance! :vanish