My FJR 1300 2005, has a rattling noise only at idle at normal temp. I have checked the valve clearance and cam chain tensioner (ok) and tried balancer gear lash adjustment, and set the sync on the throttles, nothing has stopped the noise.
Does anyone know what is causing this noise?

Ralph

If you pull the clutch lever in, does it go away?

You may also want to pull the stator and clutch covers to see if there's anything loose in there. A stethoscope can be used to pinpoint the noise to determine if it's worthwhile pulling them

rattling noise does not go away when clutch is pulled, but I will look behind the clutch
and stator covers.
Ralph