Thanks for the reply…. I’ve been doing the same. Looking through the exploded diagrams and parts lists for all the internal (to the engine) items.
The item you highlight is the cam chain adjuster and tbh, when I removed the assembly it looked like all parts were present. However, this is also my first CB550 strip so although the cam chain assembly looked complete and is now bagged up and stored, I’ll revisit it tomorrow and see if it could be part of it.
After buying the bike, I’ve only ran it in the garage to work through the PO’s long standing carb problems and then again to fit another set that Ian supplied me with.
I have done no maintenance, just straight into the stripdown process so if it is from that area, it could have been there for a long time.
I can see no shear or fatigue points on the offending item so it could be a loose item from that area…. or not 🤔
Like I said, I’ll take a look at the cam tensioner assy tomorrow and see if it could be a stray part.
Thanks again 👍