Dual Quads need tuning

[Mohuska]

I finally got my Cobra back with the new motor which now includes dual quads. I am looking for someone in the Bay area who is good at getting these things to run well. Can anyone refer me to someone? Thanks in advance.

Mike

[PANAVIA]

We would be happy to look - panavia.com we have done several dual quads, although we are EFI guys at heart - Except bob ...bob hates EFI.

[DanEC]

They are not difficult to do basic tuning on if in good shape. Or are you thinking they may need some re-jetting or secondary timing adjustments or other modifications?

Basic tuning is to think of them as one carb with twice as many barrels to adjust. Adjust the idle mixture screws on both carbs, going back and forth until you have the higest vacuum reading or idle speed. You are adjusting 4 idle mixture screws instead of two. Then close the throttle blades by backing out the idle speed crews until the blades just barely close. Then open them both an equal number of turns until your idle speed is where you want it. If it needs to be increased or lowered, adjust both idle speed screws the same amount. Both carbs need to be equally contributing at idle. For full throttle, block the linkage to full open and make sure the rear carb primary valves are fully open also. If not adjust the linkage to the rear carb to bring it full open with the front carb.

[Texasdoc]

What we did - right or wrong.... YMMV.
Others may disagree....

If you are close and it runs, follow Dan's advice. If you can't get it to run at all, block one carb off (we used a plastic bag), and tune the other carb to idle. Then block that carb off and tune the second one to idle. This will get you close where it should run - although at a higher idle than you want.

Then follow Dan's advice above. Tune for best RPM at idle adjusting all mixture screws, then set idle with idle screws. Set linkage for all the throttle blades to hit WOT at the same time.

My buddy has his set where he idles on both carbs. However, until he is about 20% into the first (rear) carb, the second (front) carb stays on idle. When the throttle is pushed >20% the second (front) carb starts to open and they both hit WOT at the same point.

[Mohuska]

Thanks for the help. I didn't mention that they are Quickfuel carbs. I have to replace the existing fuel transfer tubes this weekend because the O rings are leaking. I'll try to get things adjusted but may need a pro to get it dialed in. It is running pretty rich at idle.