Hi there, it could be one or two things, The cap locking latches jamed on the tank filler neck, or the fuel tank filler neck out of position causeing the cap to foul, and as you say just spins. Has the fuel tank been replaced or moved recently.Some filler necks need bending slightly to give better clearance for the cap removal and fitment. What you could try is slackening off the tank support strap and retaining bolt and try and move the fuel tank and its filler neck to a better position so that the cap comes off easy. then retighten up the strap and retaining bolt. I hope this is of some help for you. cheers Eric.
