2k1 cbr600 f4i 16.5k miles.
Recent work: Replaced the shift rod and shift arm since the old ones broke. Tightened up the throttle adjustment, the one near the handlebar, not the lower one near the gas tank. Also tightened up and lubricated the chain as it had gotten loose. No other work recently.

So My F1 lights come on sporadically. It blinks the 2 blink sequence indicating a faulty or loose map sensor. Recently it stopped coming on and now it idles either 500rpm or 1000rpm (temperamental) when it's warm. Additionally when I hold the throttle in first gear around 2k rpm when going cruising around a parking perhaps, the rpms are jumpy. Best way to describe is phonetically. The engine sounds like, "urururRUMurururRUM." The surge is pretty regular and you can feel the bike itself surge a bit as well. This behavior is erratic. On some rides the bike runs perfectly, while others the cold temp choke won't activate, and of course others when the FI light comes on and the bike runs oddly normal. Could a faulty MAP sensor cause all this?

I also hear a regular whish sound as I ride. It resounds from the center of my bike but I cannot exactly place where it's coming from.

 

Some updates after listening to the sound more and getting a more precise description. The sound appears to be coming from the right half of the bike. Not far right, say... center right and directly beneath me.

Characteristics:
Very regular, sounds almost like a steam engine.
It is more prominent when at steady throttle or coasting, but is either washed out or not very loud during acceleration.
The sound is made whether the clutch is engaged or not. At slow speed, I feel a slight vibration that seems to come from under and below-right of me. I can feel it through my right peg.
It has a sound reminiscent of a wire brush rubbing of smooth metal.
It seems to be somewhat dependent on how hard the engine is revving. Going 20 in 2nd gear has about the same pulse and frequency as going 60 in 6th gear.

I have no data if there is a sound in neutral, that will be what I try next.

I see a lot fo views on this thread but it seems that no one can help. Hopefully this additional data helps.

 

Sounds like a vacuum leak. A leak can cause a surging idle, set map codes, and make noises.

 

Thanks! The vacuum hose is under the gas tank right? I'll do an inspection this weekend and update this thread.

 

There is more than one hose.

 

Sigh. My inexperience shows. Good thing I got a copy of the service manual and the owners manual when I first got the bike. Thanks for helping out with my noobiness. Is it a difficult component to service? Like I mentioned I am inexperienced but I do have aptitude in quickly picking something up and applying it.

 

As 74demon said, there are a few hoses under the tank. There is one hose that is connected to the map sensor. The has a 3 pin black plug attached to it. I believe it is on the back side bottom of the air box. Sounds like a vacuum leak though.