You probably didn't get the correct size of fuel line. Try a slightly larger size. The fuel line must be a "squeezing fit, not just a push in size! To get the fuel line inside the tank, use a razor blade or razor knife, and put a 2 inch taper on the line. Then using a bit of oil on the outside of the line, push it in from the outside, into the tank and out thru the filler opening. Install the filter, then pull the line back out thru the opening you pushed it thru into the tank. Leave enough line in the tank to allow for movement of the filter on the inner end. Then remount the tank, cut the line-s to fit, and it should be ok to run and not leak!