I have been trying to work out how I can cut a bit of a seat into them. I thought I had solved the problem cleaning the burr off the inside but that is only partially fixing the problem lately. Ok so now I have tried to cut a miniscule seat using a pointed Dremel HSS tip by hand with a couple of turns. I have pushed up on the float with a lot more pressure that the fuel could ever do and the float still drops. Some of the needles I have had to grind a fraction off the end to allow the float to drop enough to allow the fuel to flow. I will see if the seats now stop the fuel or I have to throw the caps out
