nope. the jet is on the bottom of the carb. (granted, i know the dellorto carb much better than the bing). take off the float bowl. if you look, there should be a gold screw that goes up into the carb body. that's the jet. take it out. there is a very tiny whole through it (if you hold it up to a light you should be able to see some light).
those wholes are tiny and can get clogged easily (if they do, you can usually just spray the gunk out w/ carb cleaner), so don't run w/o an airfilter. the wholes are slightly different sizes on different size jets. you should see a tiny number stamped on the top of the jet (where you screw it). that's the size of the jet.
the jet allows air to come into the fuel mix and make your moped go. depending on the size carb, manifold, etc. you might need a different jet. a 14mm carb probably needs a slightly larger jet size.
for example, i used to have a dellorto 14.9. it took a 49.5 jet. then i got a dellorto 14.12, that took a 51 jet. now i have a dellorto 15.15, that takes a 53 jet. you can use different jets to lean out fuel mixtures for performance tuning.
jet sizes are different for puch, but they should go up as you get larger carbs. the new 14mm carb you have should have a jet in there. chances are, it's the right size.