Sealer fuel lines

NPT threads, go to our local hardware, plumbing store.
Buy natural gas rated teflon tape, it is usually yellow or pink.
When you wrap the threads leave the tape at least 2-3 threads away from the end of the fitting. This will prevent the tape from ending up in you carb.

Liquid teflon is nice but you need to let is set up for 24 + hrs, and it will harden for a few months.
If you have to remove the fitting a year from now you have this half pasty dried mess to clean from the threads.