I have had good luck chucking up a cotton swab (Q-Tip), dipped in polishing compound (tooth paste in a pinch) into my electric drill. You can use this to polish the carb seat mating surface so the needle's Viton tip has a smooth surface to mate with or (with which to mate if you are opposed to ending sentences with prepositions) ;-)
https://www.quickanddirtytips.com/ed...-a-preposition
Is it Friday yet?