Single Tone Heard one bike


I am concerned about a tone I been hearing under the tank somewhere..I lifted the tank to better locate the origin but with no success, I'm hoping one of you out there knows what this is all about. Is this a warning tone of some kind or am I just hearing things. The tone I hear remains constant and can only be heard when the engine is off and remains on when I hit the engine kill switch. Its a faint tone not really loud. Any suggestions?
The fuel pumps make some noise. A medium pitch whine. They so it all the time when the key is on and the switch is on. Even if the bike isn't running. This is normal. They have to more a lot of fuel so some noise is a result.
ok. so I should do nothing in regards to looking further into it? its normal to have the engine off and the key out of it and still hear the tone.....thanks a bunch fellas...:)

The tone is there with the key off and the engine kill switch engaged? Sorry I didn't catch your meaning earlier.

OK that is weird. It can't be the fuel pump if the key isn't even in the bike. Let alone of the kill switch is in the 'kill' position.

But there are no warning buzzers or alarms built into the Busa... It has to be air or fuel pressure in the fuel system escaping slowly. Schmud0811 suggested opening the fuel cap and see if the noise changes or goes away. If he is right, then the noise you hear is caused by pressure in the fuel system and opeing the tank will relieve it. To that I will add that when you lift the tank to investigate, see if the pitch of the noise changes or goes away. And check far any leaks in the fuel lines coming from the tank. It is probably nothing serious unless you find some leaks in the fuel lines.
I have the same tone. It is the fuel tank. The California fuel system has an evaporation cansiter that absorbs fuel tank vapors and effectively seals the tank. The breather line is restricted by this cansiter. My bike will sing if I park it in the sun. The tank heats up a little and the pressure builds because it can't get out fast enough thru the canister. Then the pressure escapes through the filler seal and whistles. When it is singing I can open the tank and it will release the pressure with a "whoosh". Then the singing stops for a while until it pressures up again. If nosey people ask what that sound is, I just look alarmed and say "ITS ABOUT TO EXPLODE" and run away. They usually run faster than me. Or I tell them its an a-hole alarm and would they step back away from the bike.:laugh:
I guess yours gets hotter than mine... Not heard the sound except for the fuel pump. Let's go for a ride and compare sounds.
was running on my new pit bull and cleaning the chain... shut'r down to wipe off and lookm when I heard it.... the tank was humming like you heard.... popped it w/ the key and it "popped" the cap.