[Hotfingrs]

You can write a book on this subject. Basically you're on the idle circuit until 3,000 rpm. If you were lean under 3000 then open up the idle screws a turn. There should 6 jet sizes between the pri and sec. I recently bought an LM-1 air/fuel meter and have been playing with this. I was lean until 3000 rpm, and I mean 22-1 lean, and as soon as I got on the main circuit I was in the 13-1 range. I talked to Don Gould at 4secondsflat and he said to open up the idle screws. I did this and got the A/F I was looking for and problem solved. IF you're not using an A/F meter everything is just guess work. I had tuned my idle for max vacuum, which was the old school way, and ended up waaaaaay to lean.