66 rear carb trouble
 

Hi guys hope everyone is doing well. I have a 66 setup on my car I rebuilt the carburetors myself the front 2 carbs are working fine. The rear carb is pulling fuel at an idle. I put my hand over the top of the carb it will suck my hand right against it. I am under the impression that the two end carburetors don't pull any fuel/air at an idle. I check the barrels are completely shut & checked the float height and cant seem to figure it out. Any help will be appreciated.

Too long adjusted front to rear carb rod holding the throttle blades open some on rear carb?

Most likely what Kenth said. It could be that the throttle plates were not positioned properly to seal the bore when they were originally installed.

Easy to check the rod length and bend in the center of the rod if it's too long or unbend it until the rod fits into the center of the oval hole in the front carb lever.

If the rod is not the problem. you'll have to remove the rear carb, remove the base, and examine to see if the plates are sealing. Hold the base up to a light source and see if there are gaps. To correct, loosen the screws that hold the throttle plates in place and position the plates for optimum seal. If this can't be accomplished, you may have to resort to using DAG213 like the factory used on the end carb throttle plates to achieve a near-perfect seal. PM me if you need some DAG213.

Have you got it squared up yet ?

Some have asked about using lapping compound to fit the throttle plates. While this is possible, it would take many flips of the throttle to accomplish removal of enough material to make a difference. I sometimes use brass punch and hammer to persuade the plates to fit tighter, but this does not usually accomplish much. I've found that, even with difficult cases, the use of DAG213 fixes the problem. As I've said before, I've restored many end carbs from the early sixties that still had the DAG intact on the throttle plates and bores. I apply DAG to all throttle bases, whether there is a visible gap or not.

When I apply DAG213, I brush it on the top of the plates only. I use a small brush and apply enough DAG to coat the OD of the plates so that it covers the edges, creating a perfect seal. I exercise the plates to see that the edges are covered and inspect by holding the base to a light source to check for leaks.

Here are some pictures of NOS carbs '61-'63 vintage. Note that the factory applied DAG to both top and bottom of the plates. I think the objective is to coat the edges of the plates and where the plates contact the bore. How would you like to be the guy or girl who painted this on every day?