I have a holley 4160 with vacuum secondaries and I have a problem. I hooked up a vacuum guage and i got my highest reading with the air/fuel screws turned all the way in. I didnt think it should even run with the screws turned all the way in. so if anyone can help me i would greatly appreciate it.

Carb is too rich at idle. Probably the power valve

1st make sure fast idle screw isnt making contact, make sure floats level is correct. is your throttle plate shaft straight.

[ December 17, 2002: Message edited by: bullheimer ]</p>

What kind of cam are you runnin' (you might be exposing the idle transfer slots). Also check the idle circuit air bleed holes that are in the top of the choke horn (inside choke horn toward front of carb, make sure they're not plugged up).