The Bible says that idle hands are the devil’s workshop. Our take is a little different. When it comes to setting the idle mixture on your street-driven engine, your hands will be plenty busy adjusting, tweaking, and setting several different parameters. This may not sound like something to account for an hour or so of your time, but trust us, it’s worth the effort.
If you think about it, a street-driven engine spends much of its time running with a closed or near-closed throttle. Waiting for the engine to warm up, sitting at a stoplight, cruising down the highway, or on city streets are all conditions where the throttle is just barely open. With most carburetors, these situations require a throttle opening of roughly 10 to 15 percent. This places throttle action well within the realm of the idle circuit.
That statement may come as a bit of a surprise to many automotive enthusiasts. But if your
