i was wondering whaqt are the exact settings on the idle mixture screws on an edelbrock performer carburetor?

Question

i was wondering exactly how many turns you turn the idle mixture screws for them to be in perfect sequence im at 2 right now and it seems to rich for the engine like flooding it should i lean the mixture quarter turns at a time or half turns at a time on both screws equally

Answer 1

You need a vacuum gauge to set them correctly. Hook the gauge up to intake vacuum. The engine should be warm and thermostat open, before adjusting. Turning them in leans the mixture and out makes it richer. You want to have the leanest mixture possible while producing the most vacuum at idle. Both screws should be turned in even increments. 2 turns out is a good place to start. Then with the vacuum gauge hooked up, turn one mixture screw in a half turn and see what the vacuum does. Then turn it back where you started and then a half turn the other way to richen it. Again observe what the vacuum reading is doing. By using one side you can tell whether it needs to be leaner or richer. You will then turn both screws to the same location depending on where you get the highest engine vacuum at idle. Changing the mixture will also change the engine idle speed, so after mixture adjustment, you may need to hook up a tach/dwell meter and adjust the idle speed.

Answer 2

There are no exact settings for a carburetor, as there are several things that would determine the settings, such as atmospheric pressure, engine size, and head performance. The best way to set is to turn the screws all the way in, back both out 2 turns and start your car. Then you can fine tune by turning the screws about a quarter turn each, until you get it right. Make sure you have clean air filter to, because a dirty air filter could be restricting the air flow, giving a false rich, as could a air filter that's to small.

Answer 3

Ultimately it is done by trial and error. The number of turns just gets you going. Professional have meter to check exhaust gases, for best fuel efficiency.