With respect to gas pumps: my Birkin was always very finicky filling up. I had to hold the nozzle at an angle, turned sideways, inserted as far in as possible, and just let a trickle of gas flow. Otherwise gas would splash back onto the nozzle and shut off flow. TBox56 filled me in on the solution: the stock gas tank had a small lip inside the filler at the top of the tank (round hole cut in tank, round pipe welded an an angle = oval mating surface. Trimming this internal lip solved the problem. Check to see if your tank has a similar situation.