Internet diagnosis is always tough. Could just be normal cam chain noise. Any history from the PO? Service records or known work done in the past?
Typical cam chain slap will go away when you back off the throttle or go on throttle, but is most noticeable at idle. I don't know what style CCT your bike uses, but some Yamaha's have oil & spring tensioned CCTs, others only spring. If the spring breaks or weakens, sometimes they fail to move out as wear occurs and you get more noise. Typically this will get progressively louder long before it fails. If you notice your noise increases over the next few hundred miles or so, you may want to get the dealer to listen to it, and document that visit if you have any warranty.
Typical cam chain slap will go away when you back off the throttle or go on throttle, but is most noticeable at idle. I don't know what style CCT your bike uses, but some Yamaha's have oil & spring tensioned CCTs, others only spring. If the spring breaks or weakens, sometimes they fail to move out as wear occurs and you get more noise. Typically this will get progressively louder long before it fails. If you notice your noise increases over the next few hundred miles or so, you may want to get the dealer to listen to it, and document that visit if you have any warranty.
