Whistling Gas Tank

[Akins.t@sbcglobal.net]

Hi Guys

New to the Forum. In the heat my tank puts out the most annoying whistle for some period of time after I stop. Couldn't find a thread about such. Any ideas?? Thanks

 

[twotonevert]

Your tank is a vacuum, the whistling noise is the fuel cap, if it bothers you, just lift the fuel cap and it will release.

 

[TNTom]

You could try cleaning that rubber gasket around the fuel cap. There's probably a vent somewhere in that area that could have something in it that is causing it to whistle too. I've never heard mine whistle.

 

[c10]

This would be a a vent . Normal especially in rapid temperature changes . These are built into all fuel caps to prevent the tank from deforming from fuel vapors expanding . Darker colors vent more than a lighter color like white . If you have ever seen carburetor jets gum up from old fuel this can also happen to your fuel vent over time . They are fairly simple to clean . Just be mindful of the small spring / ball bearing ( one like a BB ) not to lose them .

FYI you may chose to remove them ( some people do ) However I have experienced on removed systems at very high speeds with close to full fuel tanks a vacuum effect pulling fuel out of the vent soaking the rider quickly .

Pictures to help explain . Old school extra vent on my drag bike due to small vent holes could not keep up with Pingle Guzzler fuel petcock, and 38 mm Flat slide carbs. My finger points at aftermarket style cap vent check balls/springs .