Carb is a Holley 4777-7 650 double pumper and it is jetted right and the engine is timed properly. The car idles fine at 14-15 inches Hg @ 900 rpm. the only problem is that my exhaust smells strong at idle. I have a Vacuum gauge and an A/f ratio gauge.

I would like some input on how to properly adjust idle circuit. I kind of just turn the two screws til it starts to die then I back them off until it sounds fine. Is there a way to do it with a vacuum gauge?

 

Set them for max vacuum; then shut the car off, average teh number of turns from the bottom for both of them, then set it for max vacuum again; if you move the screws much, shut it off and average them again, and reset for max vacuum.

You want the screws the same # of turns out, with max idle vacuum. If you had an auto you'd probably want to do it in gear.

 

Thanks I will go try that, but what about the gas smell? Is that just the joys of having a carbureted muscle car?

 

Hard to say.... go get it set right and see how it is then