Having filled her up last time I was out,I took her out for a spin on Saturday afternoon.When I came back I went to fill her up and spent 5 minutes trying to get it undone.Tried pushing it down and allsorts.Got it home and greased it up.It now opens a treat.So if yours is sticky lube it or you could end up with a broken key.
Greased the locking taps and ring that moves up and down. Turn the key a few times,it becomes much easier to turn with it lubed.If you fill right up, the fuel can dissolve the grease.The bike has only done 450 miles,it looked like it has never been greased.
Sometimes if the fuel gets really low it can get a bit of a vacuum in the tank causing tight flaps - Oooo Errr - I might not feed the mrs for a while till she's really hungry and hopefully the result will be the same
Careful not to put too much lube around the flaps, it may contaminate the end of ya nozzle next time ya fill her up, then mix with the juice with disasterous results.