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Discussion Starter #1
Today when pulling into the garage and parking my bike, I heard a whistling sound. It was coming from my gas tank cap. I opened it up and the whistle stopped. I'm pretty sure the tank is supposed to have a vacuum inside, but obviously there is air seeping in through the cap. Could this be a problem?
 

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You got it Basackwards, There is NOT supposed to be a vacum in the tank and the whistling is the vent in the cap desperatlly trying to relieve one. You best clean the cap vent or your next post will be Help.....


FOG
 

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Discussion Starter #3
Hmmm. I took a look at the gas cap, and there is nothing inside or out that would seem to be clogging anything. The bike isn't quite a month old, and has been garaged whenever not out riding. There is no gunk, dust or debris to be found. It looks as clean as the day I got it.

To elaborate, the sound is a very very feint whistle. I couldn't hear it when the bike was outside the garage, so even a very light breeze could drown it out. It seems constant, didn't get louder or quieter when I was trying to locate it. But it clearly stopped when I opened the tank.

I might pull it apart later today to see if I can find anything more.

Here is a cool diagram of the Fuel Tank I found on the Kawasaki web site
 

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i'll chime in.."mine too" but mine's a bit older...i thought about replacing the cap.

if i understand the system right, it really doesn't carry much of any fuel pressure (no pump right?), and there for a vacuum in the tank would cause fuel not to flow?! whereas a buildup of pressure (my bike whistles on hot days, even without driving) would cause a raised pressure in the tank, and force too much fuel to flow..

FOg, you mentioned a cleaning, could you (or someone else) specify? i'll search too, see if the answer is around here or elsewhere..thanks.
 

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It's a Laybrinth created by a disc that covers the vent through the keyhole. The disc is whats making the noise. Remember the Kazoo you had when your were a kid?

FOG
 
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FOG said:
It's a Laybrinth created by a disc that covers the vent through the keyhole. The disc is whats making the noise.
Hey FOG, I just took mine apart and cleaned it the other day. The disc you are talking about is about 1/2" in dia. correct? Am I right in thinking that the disc lets air pass when it is in the down position and stops the flow when it gets pushed up? So the reason it creates a vacuum in the tank is that the disc is stuck in the up position? Just want to make sure how it operates...

Rich
 
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Both my Kawi bikes whistle sometimes. It is from relieving pressure in the tank. They only whistle when sitting out in the sun making the fuel expand and pushing the air out. You also may notice it right after a fill up; cool fuel from the underground tanks now sitting in a small hot motorcycle tank.
 

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Mine has been doing it from day one. I even told the dealership and they said it was normal :-\

Think I'll take it apart and clean it just to be on the safe side.
 

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Discussion Starter #12
Good to know its not just mine. It was kind of warm today, and I was in traffic quite a bit on the way home from my ride and the tank was warm from the sun.
 

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I was thinking that Maybe your dealer was right, or at least that the noise is a good thing. It indicates that the vent is working, because the disc is free to move. The whistling being the disc viabrating in is housing as the air rushes by (in either direction).

FOG
 
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