idle nosie

I had a problem like that too maself. I tightened the cam chain, and nope no help! what my problem was was thatI had excessive crank rod bearing play on the #4 crankrod. Why? The previous owner used to leave his bike idling while it was leaning. You might have the same prob if you have done all the other pieces of advice above

Had a problem noise like what you are describing. When my bike would idle the noise would sometimes get a bit louder then softer again.

Turned out the valves needed to be shimmed.