It sounds like maybe a loose cam chain to me. The stock tighteners are known to be problematic.
I'd say cam chain . Oil might not be getting to it or just going bad. The other common noise from that bike I'd rotor cup for stator and it's bearings and the clutch basket housing springs . It sounds more like the first thing though.
Yep cam chain. Before you instal a new manual or aftermarket one make sure the bike is at TDC or your bike will be toast