Best thing to do is goto a plumbing store to get some parts and redo the entire gas line , taps and all. Put thread sealer on everything including the carb bowl drain screw. I used Permatex gasket maker to seal all my gas line threads.
I am going to do my fuel line in copper eventually but this is how my line looks atm :
On that tap into my gas tank there is an o-ring behind the washer too. That was my problem spot and now its dry as a bone.