Anybody have any experience of this? It is a 2014 XMAX 400 and I feel that the driving position is slightly cramped. Have done a lame attempt to remove the seat hump, but the 10 mm screws under the seat just rotates without coming off.

I tried to remove the seat hump on my X-Max to clean under the backrest and had the same situation. Got one screw out but the other just kept turning. Sorry, that doesn't help your situation.

No it certainly does not.

Unfortunately the seat hump position is not adjustable like the TMax or Majesty...
I could do with putting mine back an inch or so...
Perhaps the captive nut in the hump is just turning...
Try a little upward or side pressure - may hold the captive nut still enough to undo...
May then have a problem with re-installing - or a fix with a glue gun?
<Sent you a PM...>

Sorry, have been away a while from the forum. Thanks for your responses, and I will try again with the side pressure approach. mac65, you got at least one screw out so it shouldn't be impossible! Was there a nut to that screw, and how did you get the screw back? I got to get that hump off the scooter or a get a new one...