[Gregski]

Adjusting the Idle Speed and Idle Mixture simultaneously (it really takes Two To Tango here)

so the recommended starting point for most carbs is 1.5 turns out from bottomed out, in other words Idle Mixture Screws all the way screwed in, mine just happened to be set there - one and a half turns out they were

Note: my four barrel carb has two Idle Mixture screws one on either side of the front float bowl, some fancier carbs have four Idle Mixture screws, two in the front float bowl like mine, plus two additional screws in the rear float bowl as well

my truck was set to idle at 700 RPM - aka the Idle Speed screw (which does not just control RPM but opens / closes or hides and exposes something called the transfer slot(s) (ubber important)

the recommended setting is .020" or making the slot look like a little perfect square (Note: it is over exposed in the picture below, in other words it is too large) the pic below is just an example it is not my actual carb