46mm weber air adjusting screw setting
 

I'm trying to adjust the air adjusting screws (locked in place with a nut) I disconnected the linkage, backed off the idle screw and turned the air adjusting screws all the way in. Where should the idle mixture adjusting screw (with spring) be set (if it matters) while I'm trying to adjust the air adjusting screws.
With the everything disconnected and the idle screw backed off the motor is idling around 1000-1100 rpm.

I have this post permanently bookmarked and have found it to be extremely helpful in my carb adventures. http://forums.pelicanparts.com/showthread.php?s=&threadid=67957&highlight=bastard s

Thanks for the link, great info.

There is one potential issue that I didn't see addressed in the excellent post by John, and it is clogged idle jets. If an idle mixture screw isn't causing the engine to respond as described, there is probably a clogged idle jet, and it's easy to check. On the cylynder(s) that aren't responding, slowly loosen the idle jet holder until the jet begins to screw out, about 1/2 turn. If th idle jet is clogged, the engine will begin to perk up when that cylinder begins to recieve the right amount of fuel. If you go too far, it will flood the cylinder a little bit, and the RPM's will drop again. If you find a clogged jet, pull it out, make sure you don't loose the O ring, pull the jet out of the holder, blow from the inside out, and the sight through the hole towards a light to see if it's unclogged. It is very common for idle jets to clog, they are the fuel's first destination after the fuel bowl, and they are the smallest orfice in the carb, so they often clog with any tiny little piece of dirt that finds it's way into the fuel bowl, especially after R&Iing any part of the fuel system.