Teflon tape works just fine with gasoline, but teflon tape is not needed on tapered pipe fittings, that's why the design is tapered, an interference fit to seal. Not only that but all it takes a small piece of teflon to come off and hold the float needle off its seat and its flooding. Sadly 99.5 percent of the time what you are describing is a split carb housing. Its a piss poor design, because the pot metal carb housing is softer and weaker than the fuel filter, and all of the manufacturers are guilty of using it. Helicoils will not work in this application because they wont seal. and I am not cross posting this ether
Whitelightning