Gt500 fuel filler cap

[Yorkshireman]

I know these are common across many GT models so I’m hoping someone can help.

I’m having a problem with the filler cap on my GT 500.
I can’t get it to click into position to properly seal the fuel tank. It seems like I can’t press it down enough for the lock mechanism to hold it tightly closed.
It doesn’t look like it’s been messed with, though there is a piece of plastic tube over the 3mm pin that the lock engages on. This isn’t a tight fit over the pin so I don’t think it’s a standard part. I’ve tried it with and without this in place and it makes no difference. The lock itself is fine, it moves freely and the button works as it should and when the cap is open I can push it up into the position it needs to be in to close the seal properly.
The only way I can fill the tank and ride without fuel leaking out the top is if I take the front securing pin out and remove the cap, then press the lock into it’s upper position, then place the cap back on the fuel tank and put the pin back in!! Hardly ideal don’t you think.
Any suggestions would be greatly appreciated.

[Yorkshireman]

Bit of an update for anyone who may be interested.
I visited Stafford show at the weekend and I took the fuel cap with me in the hope of comparing it to other ones there which I was able to do. Basically there is nothing wrong with my fuel cap, it just needs a smart smack and it will lock down and seal the fuel tank, something which I was reluctant to do and still feels a bit drastic. I saw three fuel caps on different bikes and only one closed with a gentle push, ironically on a Gt500, the others needed a good whack.

[karl pa]

My GT250B is the same way, you can actually see the top of the tank give when latching the cap. Most of my others close with less pressure. I was wondering if it had issues, or if that is just how it operates.