Gas tank whistle sound?

[Djm2u]

Just wondering if any of you have had issues with the Gas tank whistle sound? I have an 2004 750 Kat. In the sun it whistles like crazy due to heat expantion.

I have checked the breather tube for restrictions but all seems well. Just curious if anyone else has this issue.

Thanks,
Darren

[chrisman826]

hmm i get this sometimes when my bike sits out in the sun for a little bit and it is REALLY hot outside, like, 101 degrees (which is what its been here the last few days in tx). Like, when i take it to work, or i run into a department store for i bit. When i Return, I hop on my bike, and when I lean it upright, I hear air release from the gas cap. Its kinda like this.. PPPpFFFFFFSHHHHOOOOOOOOOOOOOOOOOOOOOSSSSHHHHHHHHHH HHHHHHHHHHHHHHHHH!!!.............................. ......................
Im a little curios if this is a bad thing as well, allthough, mine doesnt whistle.... it just does it that one time after sitting when i lean it upright. Would be kinda cool if it whistled tho......hmmmm.........