All the way in and you will cut off the fuel.
Also, you adjust these in 1/4 turn increments so don't just go spinnin' it around a bunch of times.
Less than 1 full turn out = go down a jet size. Over 4 full turns out = Go up a jet size.
In order to find out you must count how many turns it takes untill the mixture screw bottoms out (NOT TIGHTLY, just untill it seats). Then back them out the same amount of turns, back to where they were. Whala... You now know your settings!
http://www.bonnevilleamerica.com/forums/...mp;page=0#89123 This has info by Greybeard on how to adjust the mixture screws.
Also Airbox modification instructions are here too.
At 130 mains, I would think you will need to rejet if you do manage to get any more air to the carbs.
