I've been getting this whistle/flute like. what is it and how do i fix it?

not my bike but it's the noise:

there's a comment on the video calling it cavitation is that actually what it is? how do i fix it? it sounds like a not good, bike-ending noise thing.

 

Sounds like a fuel pump problem to me, it makes then noise and then stops when you switch the ignition on (when the pump primes).

I doubt anything is gonna go bang..

 

no no, theres the priming noise but after the bike starts you hear the flute noise rising. i had it... then it went away.. t came back then it went away??? i wanna say it's heat/temperature related.. but have nothing to back it up with.

 

Does the sound change with a low vs. full tank of fuel?
Ever try removing the gas cap when you hear it? Any change?

 

oddly enough... it went away. but it is also not 97 degrees. but i'm sure it will return. i'm concerned. the bike aint been right since that 24 hour madman ride i took to key west.

 

Does that mean it went away on its own, or did you fill the tank?

 

on its own. it very well could have been related to the gas level. not sure

it would make sounds like it was depressurizing when i turned the bike off. i put the bike away, take it out a few days latter no sound....

 

funny, my 2010 48 does that every so often. I hear it whistling when I start it up and then it whistles for a mile or 2 and goes away. Always wondered what it is. Only does it now and then. Not sure if it's from sitting outside in the sun at work for 10 hours and getting the tank hot and building pressure in the tank. Mine only does it when I leave work.

 

My Nightster does that when the tank is getting close to empty.
Only started after I switched to the 48 tank though.

 

Heat related, Gas expands the clue would be 97% does it and cool it doesn't...