Carter 2bbl Carb OverhaulI belong to this forum for the simple fact that everyone here loves their 1st gen Charger. I know we are a very diverse group of enthusists rangeing from those who prefer to drive and not tinker with their cars to those like myself who will probably rebuild every single item by themselves.
I know many times we refer someone to the repair manual when asking about a technical question however sometime the repair manual does not have all of the answers. Also some people prefer personal experiences over reading a book.
What I would like to do is share with everyone some of my experiences as a professional automotive repair technician and a 1st gen owner. My hope is to increase everyones knowledge and operation of our cars.
My first effort is the rebuilding of the Carter 2bbl on my '66 273. This vehicle has been basically sitting since 1985, needless to say the carb needed some attention.
Before we begin here is the theory of a carburetor. A carburetor works by pressure differental. Most carburetors have six circuits or systems that allow fuel to flow through the carb. I will address each as I progress through the rebuild.
This is what I started with. Initially the accelerator pump was not functioning.
I start my disassembly from airhorn and work my way down. I lay my parts out in the order I disassemble them. A good picture helps on reassembly.
As you can see this is bad!
On some carbs you need to check the mating surfaces for straightness. On this carb about the only place is the throttle body. There was no light across the area where the idle circuits are.
Here is a look at the end of the idle circuit. The small hole left of center is the idle discharge port. The slot above is the transfer port. When the throttle plate is closed only the round hole is exposed to the manifold vacuum. As the throttle opens th
Here is a look at the base plate and gasket. You can see the idle circuits are cast rectangular with the curve towards the center. The ported vacuum is on the right.
Here's what the base plate looks like with the gasket in place. On any carb you rebuild be sure to look for worn throttle bodies. The bad ones are Q-Jets and Holleys. This BBD was fine.
You can see the relationship between the circuits that are in both the throttle body and the main body.
The passageway next to the arrow is the manifold vacuum that is applied to the power piston.
These four screws hold the airhorn to the main body.
These are the screws that attach the main body to the throttle body. The long ones from the top and the short ones from below
I started my disassembly by attaching the throttle body to the main body. I will leave these screws loose until I get the entire carb assembled
Here's a look at how the long ones go. The vacuum port dead center is for the choke pull off and the large one is for the PCV
Here is a look at the main jet and mixture rod. The mixture rod has steps that change the amount of fuel that flows from the float well into the main well.
Here is the main booster assembly. The brass tubes are the main circuit pick up tubes. The fuel is picked up by the tubes and distributed to the outlets in the boost venturi.
You can see the passage from the tubes on the left side to the discharge on the right. If you see fuel exiting the discharge tubes at idle you have too high of a float level, throttle too far open or main air bleeds plugged.
These are the idle pickup tubes, they also sit inside the main well with the main pickup tubes. The openings in these tubes are very small.
These two screws hold the main discharge assembly into the main body. They also double as the idle air bleeds and the idle circuit between the booster assembly and the main body.
Here is the majority of the idle circuit. The difference in pressure between the main well which is atmospheric and the intake manifold causes fuel to flow up the idle tubes and down the hollow screws to the idle discharge ports.
The main well is the kidney shaped opening in the main body. It connects to the main jets via a passageway in the bottom of the main bowl. For the main well to have adaquate fuel the float level needs to be perfect. At higher RPMS a restricted main jet c
More from my carb rebuild
When doing a carb rebuild you may find optional gaskets. Check closely to make sure you install the correct one. Mine was the bottom one.
This is the boost venturi assembly. The holes in the front are the accelerator pump discharge holes.
The boost venturi assembly is screwed in place. The arrow is pointing to the main well air bleed.
As you can see the length of the new inlet assembly on the left is longer. It took some adjusting to get the float level right.
When adjusting the float make sure the float retainer is in place.
This is the power valve. The stepped metering rods move up and down inside the main jets and change the fuel flowing into the main well.
The power piston assy is in place. The hardest part here is to insert the metering rods with 52 year old eyes.
Don't forget the accel pump check ball. No ball no pump discharge.
We are almost ready to put the airhorn on. I had to stretch the accel pump spring to get the pump to work properly.
The airhorn is on and the screws are tightened. The brass tube in the middle is the float bowl vent.
This should be it.
I clean this carb with NAPA carb cleaner. I left the carb in the cleaner for a day and it did OK however I was not totally happy. I put some mild phosphiric acid in my ultrasonic cleaner and in about 1/2 hour they were perfect.
I installed the carb on the car, set the dwell and timing and she purrs like a kitten. No more hesitation.
I hope everyone enjoyed this post and it may inspire more of you to rebuild your own carbs.
This is one of the accel pump settings. My linkage went into the middle hole. Anytime you adjust a linkage do so at the bend.
This shows how when the choke closes it raises the fast idle cam.
Don't forget to tighen the two base plate screws. This also shows the idle needle screwed all the way in on one side and about 2.5 turns out on the other side.
It is ready to bolt onto the car.