Looking for ideas from knowledgeable souls to help me get to bottom of this:
I've eliminated these sources of clacking noises:
- cam chain tensioners/guides.
- timing chain tensioner/guide (front of motor).
- TB butterfly spindle bearings - L & R.
- TB vacuum imbalance.
Symptoms:
- starting from cold: no noises; idles like a sewing machine.
- as engine warms up, clacking noise slowly appears, and gets progressively louder until engine is hot.
- when riding, noise is quite audible, but only on deceleration, below 3000 rpm.
- feel the clacking through the bars - fairly strongly.
- clutch operates smoothly. No change to noise whether clutch in or out
Oops: left out that the noise is coming from the clutch housing, immediately behind the engine.
Have stethoscoped poor old HerrFlick to death, and now fearing I might have to perform major explorative surgery.

Has been driving me even more batty than usual. Arrrgggh.

37,000 mi. (67,000 km).
Cheers and thanks.
John C.