OK So pulled the back wheel checked and cleaned everything tensioned chain and tried again….No good! Did 5 days in France which was lovely but buzz noise persisted.
On return I decided for the sake of 15 quid to replace the front sprocket….Ideally you replace both sprockets and chain at same time but as only done 4/5 k miles on these happy to make an exception and also just to see if things improved.
When I compared the new to the old the old had indentations from the chain in the rubber damper. Maybe the chain was too tight or maybe it was a duff one. Good news on the test ride as now the buzzing is no more!
I had fitted DID chain with JT sprockets this time but in future will pay the extra for the Yam parts.
Happy riding