Weird whistling sound after shutdown...

I'm wondering if this is a normal thing or not... every time I shut my '97 down, roughly a minute after shutdown, I hear this little "skeeeee..." sound. I suspect it has something to do with the parts of the emission control system that operate under a vacuum, like the PCV, ACV, etc.

Anyone else hear this weird sound after they shut their bike down?

 

I have an '02 that does exactly that. It's partially what you think it is: emissions system and vacuum systems relieving positive/negative pressure. The other part is fuel tank: if you pop the lid off your fuel tank, the sound stops immediately. Perfectly normal and healthy.

 

Normal??????

I also have a 97 and I don't hear the noise at all. Am I broken or does it matter if you got a California bike since they seem to have additional emissions stuff on them?

 

I used to have an 87 FZ750 Yamaha that would do that whenever it felt like it. The bike could be sitting for days, and then if you open the garage door on a warm day and wait about 10 minutes, the whistling would start. It was the vent in the fuel cap. My buddies 91 FJ1200 does it as well. Almost a crying sound.

 

Yup, that's it. I've never had a bike as technologically advanced as this before... I guess I'm just not used to it.

My Hawk GT is a California model, but I ripped all that junk off and plugged the necessary holes... which is why I'm familiar with the emission control system at all.