Chris`s85Z28

I have a Holley 600 vac. secondary. carb list 1850-2. I can not get it to idle under 1500rpms and it`s rich as hell I rebuilt it last summer and never ran it till today, I have the idle mix screws out 4 turns and the idle screw is turned down almost all the way and when she`s running it`s just pours out black smoke, it`s just a clould of black smoke behind my car it`s REALLY rich I can`t get the floats any lower. if I could get 1/2 the gas to run though it, it would be good but I can`t lean it out.

p.s it has never back fired yet.

Stephen 87 IROC

Could be any number of things.

Take the float bowls off. Turn them upside down and blow into the fuel inlet. The needle and seat should be closed and you shouldn't be able to blow through them.

Check the air bleeds. They could be plugged and will cause a rich condition.

4 turns out on the mixture screws is way too much. 2 is about the maximum and 1-1/2 is normal.

Idle screw turned down? That should be increasing your idle. You probably have the butterflies open so far that the transfer slots are exposed.

angel71rs

One of the things I love about Holleys is that you can pull the needles out the top for cleaning. Give them a blast of carb cleaner and pop them back in. About 3 threads showing (without a gasket) is a good starting point until you can fine tune it with the sight plugs. I start at 1 1/2 out and go in. Usually end up 3/4 to 1 turn out. Is there a chance the choke mechanism is not all the way out and causing your fast idle?

Chris`s85Z28

Thanx for the fast replys. Well I have to have the idle mix screws out 4 turns and the idle screw almost all the way down or it wont run at all.

I`ll try the tips you guys gave me on the weekend, but the needle valve in the floats are brand new.

after i turn it off it just pours this white smoke out of the carb and it`s so rich the carb gasket was soaked when I took off the carb. But after about 3000rpms it starts to smooth out it`s still rich as hell but I can tell by revin it inbetween 3000-4000 rpm`s that the holley has WAY more power then the Q-jet. it even sounded more powerfull. I hope it`s just WAY out of ajustment because I REALLY want to run the Holley.

Dirt Reynolds

Agreed with angel and Stephen - check the needle and seat. Thats what it sounds like to me is the problem. I've had that happen once on my Holley 3310 750 vac sec. It started in a parking lot all of a sudden, and black smoke poured out and the car ran like crap. Fortunately at the time, I was right in the parking lot of a speed shop, and one of the mechanics who was standing around BSing with the guys came over, and had me pop my hood. Tools in hand he replaced my secondary needle and seat with a new one off the shelf from the shop, set my fuek levels and voila - back in action running great.

We figured the carb just picked up some crap that got by the fuel filter and a tiny piece of junk is all it takes to cause problems with the needle and seat.

slimdawson

Also check your fuel level. And make sure the floats themselves are not filled with gas.

Make sure fuel pressure is not too high as well.

jzajac1

If your power valve is blown it will simply run very rich. check it......