Welcome from Oz. Your tank is not venting and this will cause you to starve for fuel.
Your bike is designed to run with a pressure in the tank from fuel vapors. It will give a whoosh sound when opening.After a ride in warm weather, there's a whining noise coming from my '91 Interstate. After checking electrical components, I found the noise to be coming from the gas cap. When opened, it sounds like opening a fresh can of coffee and the sound is gone. I'm wondering if the fuel cap gasket is bad or do they normally make this noise? Also, accelerating from a stop, the engine hesitates. Vapor lock?
The venting is normal. Although it's not suppose to be audible under any circumstances. I'd replace the cap if it's in the budget.The venting is normal although not usually audible while riding.