I have noticed that on my '11 C14, the idle will hunt, go to 2000rpm, down to 1000rpm go up and down. It is most noticeable in eco mode, goes away after a few minutes. is this normal?
That is not atypical for some gasoline engines but a 1,000 RPM swing seems kinda large. Lots of things could cause this- type of gas, not running right grade, ambient temps, ignition miss, flaky plug, problematic sensor.... others can make additional suggestions.
I don't see much fluctuation at all on my 2011 Concours. Eco mode runs very lean, so it is likely to amplify any variance that was present.
You should report:
1) Exactly how old the bike is
2) How many miles on it
3) Has it always done that
4) When did it start
5) What type/grade of gas being used
6) Where you are located (temp/altitude hints)