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ChevLoRay · 08-03-2003, 09:56 PM

Basic carburetor adjustment: There are two idle air screws on the base of the carb, at the front. Turn them in until the just barely seat (stop turning). Then, back them out 2 full turns. This is the basic adjustment, and assumes that the rest of the carb is working properly.

Fine tuning the carb may require a vacuum gauge, a tachometer, or both, since you will be making that same idle are adjustment but tweaking them to get the highest vacuum and a smooth idle, probably about 700 RPM's in Neutral, or about 650RPM's, in Drive at idle.

These are just ball-park figures. If you truly are not comfortable making the adjustments, by all means let someone do who is capbable. OH, make sure the ignition system is up to snuff. Carbs get the blame for ignition problems, and ignition systems get blamed for carb problems. If you don't know which one is the problem, get someone who is capable, to help.

08-03-2003, 09:56 PM	#3
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Basic carburetor adjustment: There are two idle air screws on the base of the carb, at the front. Turn them in until the just barely seat (stop turning). Then, back them out 2 full turns. This is the basic adjustment, and assumes that the rest of the carb is working properly. Fine tuning the carb may require a vacuum gauge, a tachometer, or both, since you will be making that same idle are adjustment but tweaking them to get the highest vacuum and a smooth idle, probably about 700 RPM's in Neutral, or about 650RPM's, in Drive at idle. These are just ball-park figures. If you truly are not comfortable making the adjustments, by all means let someone do who is capbable. OH, make sure the ignition system is up to snuff. Carbs get the blame for ignition problems, and ignition systems get blamed for carb problems. If you don't know which one is the problem, get someone who is capable, to help. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.