My bike hs developed a high pitched ringing noise. Can be heard at idle, get drowned out by revs but gets louder at mid-rpms?
Anyone got a clue what it could be?
A lose fixing, worn spring, worn tensioner, worn chain. The list is endless …
where is the noise coming from?
Could be a bearing on the way out…
Bike is coming up on 5000 miles so I kinda doubt its wear and tear.
Sounds like its coming from the engine…
Tinnitus? 
Oil levels ok?
I last checked it a few days ago and it was fine.
The engine is a big place …Cylinder headCylinders CrankcaseClutch housingGearbox
Assume nothing wear and tear starts as soon as you’ve put one mile on the clock
probably something broke off in the exhaust. I had this twice.
Does it have any type of exup valve in the exhaust system?
I would turn off engine and give the exhaust a few taps along it with a bit of wood or rubber mallet and see if there are any rattles .