I agree more info needed on these problems, did you just buy the bike? it sounds like a vac leak could be causing two of your problems this was mentioned earlier. Is the noise noticed at idle without moving? does the noise speed up with the speed of the engine? so far I would guess a valve adjustment. and or timing belts?In my opinion if this bike is new to you that it needs to be gone over to get a clean bill of health.I have a three problems.
The first one is the engine surges at idle.
The second one is the noise in the engine or transmission area after the engine warms up.
The third one is the engine whistle, not air from running,