The little spring that holds down the key cover on the fuel filler cap is long gone. Consequently, the little flap keeps on lifting due to wind pressure.

Can I:

1. Remove the existing gas cap
2. Rotate it 180'
3. Bolt it back on

so that it is effectively reversed? This would make the flap open *forward* rather than backward, and would make it impossible for the flap to lift due to wind pressure if the bike is moving forward.

Thanks.

It's not something a GS500 owner would normally do. But since you've figured it out already, why not try it and let us know if it works?

The screws will line up and It's just a round hole underneath. As long as nothing blocks the drain tube off... it should be good.

Turns out that although the outer hole is round, the gas opening is placed asymmetrically, meaning the screws won't line up and the cap won't fit the tank if it's reversed. Bummer. Oh well.

Well, now we know. Thanks for posting your finding.

It should be possible to make a new spring for the flap. I haven't done it yet, but I intend to because mine is also a bit loose.