You should try filling a Supersport - not only does it suffer the same short neck problem but the rear wing means you have to hold it at an awkward angle - usually with the other hand underneath.
First time you go to service it, tell the guys to check if the pipe no. 12 is not full of gasoline.
http://www.aero-racing.co.uk/partsbooks/supersports/fuel%20system.htm
