These bikes are getting to an age where the clutch cush drive rubbers will start to wear out.
It's possible that this is where the rattling is coming from.
Whip the clutch cover off and try and rotate the clutch basket by hand. There should be no discernible play in it.
These rubbers sit behind the clutch basket
[image: PXL_20260527_183632013.jpg]
Sandwiched between the primary gear.
[image: PXL_20260519_091204926~2.jpg]