camaroneil

guys,
just fitted a holley 600 vac sec carb last week,
it's a brand new carb that has only ran a few times on my camaro,
thing is,,,,,,
i can start the car up in near freezing conditions with no choke and it runs fine,
i have the mixture screws out 1 1/2 turns,
any ideas????
thanks,
neil

Brettmc

This is a problem? :confused:

Brett :thumbs:

camaroneil

it drives great hot and cold without any choke,
seems to be using a bit more fuel,
i was thinking of pulling the plugs tonight and see what they look like,
neil

lars

The Holleys are set up just a tad on the rich side, but this is usually not a problem. If you lean them out you will often get into an off-idle stumble problem.

You might do 2 things:
First, check your idle mixture screws. Most stock Holleys will idle best at about 1/2 to 3/4 turn out on the screws. 1-1/2 sounds a bit much, so try leaning it out a tad after the engine has warmed up.

Second, make sure the secondary adjustment screw has been properly set. The primary throttle blades (idle speed screw) should be adjusted so that about .020" of the transition slot in the throttle bore is visible below the throttle blades. The secondary throttle screw then needs to be set to give the secondary blades the same throttle opening as the primary. This will flow a slight amount of air through the secondary side and will assure that your mixture runs correctly.

camaroneil

thanks for that,
will try tonight,
everywhere i've read says to start at 1 1'2 turns, thats why i tried that first,
thanks,
neil

The Dude

I think 1 1/2 turns out on the idle screws is just one of those rule-of-thumb, ballpark kind of adjustments--the car will idle like that and it gives you plenty of room for fine tuning. My Holley generally likes its idle screws about 1/2 turn out. (At least that's where they always wind up after I'm done fiddling with it.)