Carb gurus needed!! Edelbrock 1406 tuning

[75ranger]

Hey all-

Have been tuning up the beast this weekend and have a question for the carb gurus.

Edel 1406/Performer 289 manifold. Relatively new and have not gotten it just perfect yet.

Here is my question. I was running really rich. I got the timing set via vacuum gauge and am pulling about 17. I went to adjust the carb mixture screws and started with them 2 full turns out and the idle at around 700rpm. Ended up peaking when turned them in about 1/2 turn for 1 1/2 turns out. I read somewhere that if you bottom out the mixture screws, it should kill the motor. Mine doesn't .If not, you are too rich and need to rejet the carb.

What is the general opinion out there?

 

[bronco loco]

I don't have an Edelbrock, here is the manual if you do not have it http://www.edelbrock.com/automotive_new/mc/carbs_acc/pdf/carb_owners_manual.pdf

 

[broncnaz]

I really dont worry about what the exact turns of the idle mixture screws are but it is true that the engine usually dies when they are turned all the way in. But as long as you are getting a change in idle speed and vacuum when you turn them then the circuit is working. Other things can affect the idle speed like the idle speed screw if its set to high then you wont kill the motor when bottoming the idle mixture as the carb is running off the transition curcuit.
I had a 1406 on my 73 for a little while my 73 is slightly built and I still needed to lean it out 4 steps.

 

[jckkys]

The jet size has no effect on the idle mixture. The jetting is usually too rich on performers I've installed so your likely right about that. Performers come with an owners manual in the box that explains how to calibrate the carb to a particular engine. If you didn't get one, it can down loaded off the Edelbrock web sight or your local speed shop probably has one they can give you. There's no reason to believe your carb won't work fine once it's set up.