Its the air pressure as you shoot the petrol into the tank there is nowhere for the air to go but back up the tube . The old +8 had two fillers open both and the air went out of one while the petrol went in the other, it was handy you could pull up at any petrol pump .
Mine has the same problem and I just tell the people it will take time, they dont seem to mind as they oggle the mog A tip is to pull the nozel out of the filler little bit at a time till almost at the top that way the air can get out a bit better . You will have to learn to be Billy The Kid with the trigger give it a shot and stop , but beware when its near the top or its allover the Mog ( YOU ONLY DO IT ONCE ) But ask yourself whats 10 mins standing when you are going to get a ride in your mog and listen to the engine , you could stand 10 time longer for a ride in a bus and listen to someone using foul language . I know what I would have first.
