G'day Mate,
What motor are you using, have a look at the end of the needle valve, there may be a hole in it, with a grub screw, all you do is loosen the grub screw & insert a suitable length, just long enough to bring it outside the cowl, of music wire with a 90 degree or circlular bend in it, & I like to grind a small flat in the wire for the grub screw to grip onto, lock it down & away you go.
2nd question: the answer is yes fuel in thru the carb line overflow out the exhaust line.