Bob, The idle mixture screws do not directly control idle speed. They adjust the mixture at idle. If you just want to tweak your idle speed, use the throttle stop screws. Please go read my entire carb synch procedure on my website (www.birdmanferrari.com). Don't go tweaking the carbs until you are sure what everything does!! The idle mixture screws make the idle mixture leaner when you turn them in (clockwise) and richer when you turn them out (counterclockwise). The idle mixture screws adjust how much fuel gets from the idle jets to the first progression hole in the carb and therefore how rich or lean your mixture is at idle. You asked me "why did the idle change when I changed jets," and I said because the mixture changed, and you might want to tweak the idle mixture a tad. If you just want to leave well enough alone and make the idle higher, go to my carb synch procedure and read the part at the end about setting the idle speed. However I **STRONGLY** urge you not to just tweak the idle but read the procedure, follow it through, and synch your carbs first. You need to know they are synched before the car will ever idle right. Trust me, it's not that hard and you will be amazed by the results. Birdman
The Bird is right. If you are a little anxious, just determine how many turns each one is out right now. Screw each one in until it stops, making sure to count the turns. That way you can always go back to where you were when you started.
