Metallic Rattle M1100S

Hi,

Has anybody got what is best described as a "metallic pinking" sound at around 5k rpm.

Makes me think that something has come loose in the engine but told it might be just the standard exhaust system that runs very lean and produces the offending sound.

No noise at lower revs but sounds bad enough for me to think a bearing has blown in the engine, gearbox or clutch. Engine does not feel down on power.

Any thoughts?

Cheers