
How to Install a Carburetor in a Classic Mustang
Last Updated August 8, 2023 | Kevin BrentIf you're looking to upgrade your Mustang's carburetor or need to replace a faulty one, installing an electric choke carburetor can be a great option. An electric choke carburetor eliminates the need for a manual choke and provides a smoother start-up, especially in colder weather conditions.
If you're not familiar with carburetor installations, the process can seem intimidating. We'll walk you through the steps required to hook up an electric choke carburetor to your Mustang, including the necessary tools, precautions, and techniques.
Mustang Carburetor Install Steps
For this installation, we chose the Cast Finish 600 performer series electric choke carburetor from Edelbrock. This Carburetor features an adjustable valve secondary for simple and accurate tuning, along with optional single or dual fuel inlet for plumbing flexibility.
The carburetor you choose may be slightly different, however, most direct-fit replacement options will have the same installation steps. Make sure to check the manufacturer's recommendations for your unit before you begin installation.
Since we're dealing with fuel, safety comes first! Make sure you disconnect your Mustang's battery before you begin. The best time to replace your carburetor is when the engine is cold. Otherwise, you may burn your fingers or cause unnecessary fire hazards.
Parts and Tools Needed:
- Blade or Gasket Scraper
- 1/4" Hex/Allen Wrench
- 14 mm Shallow Socket
- 1/4" Box Wrench
- 7/16" Box Wrench
- 20 Star Driver
- Screwdriver
- Vice Grip Wrench
- Tape Measure and Marker for Labeling
Step 1: Remove Old Air Filter
Pop the hood of your Mustang and remove the air filter from the current carburetor.
Step 2: Disconnect Fuel Line
Locate the fuel line on your old carburetor. Place a rag beneath the fuel line to catch any fuel that spills out. Remove the fuel line clamps using a screwdriver, then disconnect the fuel line. Plug the fuel line with a wooden dowel or a center punch to stop any fuel from coming out and prevent contaminants from entering.
Step 3: Disconnect Throttle Linkage
Use a 7/16 inch box wrench to disconnect the throttle linkage from the carburetor. Move the linkage out of the way for the following steps.
Step 4: Disconnect Carburetor Hose
Disconnect the Mustang PCV valve from the carburetor hose attachment point.
Step 5: Remove Throttle Return Spring
Remove the Mustang throttle return spring from the carburetor. If the spring is rusted or defective, it may need to be replaced.
Step 6: Remove Distributor Vacuum Advance Hose
Remove the distributor vacuum advance hose from the carburetor. Make note of any other vacuum hoses, mark them using the tape and marker, and remove them from the old carburetor.
Step 7: Remove Positive Wire from Choke
If you have an electric choke, remove the positive wire from the choke.
Step 8: Remove Old Carburetor
Remove the four nuts and washers from the bolts holding down the carburetor using a 1/2 inch box wrench. If the bolts are rusted you may need to replace them. Then, remove the old carburetor by lifting it up off of the Mustang intake manifold.
Step 9: Clean Intake Manifold
Carefully clean the intake manifold surface using a blade or gasket scraper, removing any remaining gasket material. Be very careful not to allow any debris to fall into the intake manifold. Stuff the intake openings with a clean rag to make sure nothing falls in. If necessary due to age and rust, remove the old studs/bolts from the intake manifold and replace them.
Step 10: Attach New Carburetor
Insert a new carburetor gasket onto the intake manifold. Place the new carburetor on the intake manifold, and put the washers and nuts on each stud/bolt. Then, tighten them down.
Step 11: Connect Throttle Linkage
Connect the throttle linkage to the carburetor. Then, reattach the return spring.
Step 12: Plug Manifold Vacuum Port
Your carburetor has four vacuum ports: one large manifold vacuum port on the back of the carburetor and three ports on the front. The manifold vacuum port on the back of the carburetor is used for things like power brakes. If your car doesn't have power brakes and you don't have a need for the manifold, plug this port with the hardware provided in your install kit.
Before you bolt the carburetor to the intake manifold, use some thread locker and insert the plug to seal off this vacuum port, as shown below. Use a 1/4 inch Hex / Allen wrench to tighten the plug.
Pro Tip:Most manufacturers do not recommend using the rear port for the PCV valve.
Step 13: Seal Off Extra Vacuum Ports
The front of the carburetor has three vacuum ports. The larger one in the middle is a manifold vacuum port for your PCV valve. The vacuum port on the left is a timed advance port. Connect the vacuum line from your distributor to the left port if you use timed vacuum advance.
The central port is slightly higher than the port to the far right. The far right port is for manifold vacuum and travels down to your modulator valve. It's required if you have an automatic transmission.
If you don't have an automatic transmission, simply block off the port to the far right of the carburetor with one of the supplied plugs.
Step 14: Connect Vacuum Lines
Connect your Mustang distributor vacuum hose to the slightly higher timed advance port on the left of the carburetor as pictured below. If you don't use vacuum timed advance for your distributor, block the port with a supplied plug.
Next, connect your PCV valve vacuum line to the larger port in the center of the carburetor. Plug the port to the far right if you don't have an automatic transmission. Otherwise, connect your vacuum line from your automatic transmission to the far right port.
Step 15: Connect Fuel Hose to Fuel Line Fitting
Locate the straight fuel line fitting on the left of the carburetor and connect it to a 3/8 inch rubber fuel hose. If you don't have a Mustang 3/8 inch fuel line hose, you may need to purchase several feet of it. Do not try to attach a 5/16 inch hose. It won't fit and you're just asking for trouble later on when the fuel leaks.
Step 16: Install New Fuel Filter
You must install a new Mustang fuel filter! If you don't, you'll likely void the warranty on your new carburetor.
Connect the new 3/8 inch fuel line to the straight fuel line fitting on the carburetor and use a 3/8 inch clamp to attach it to the fitting. Give yourself enough fuel hose length to install the fuel filter without causing the hose to kink. Install 3/8 inch clamps at each connection. Attach the rubber fuel hose to the steel fuel hose coming from the fuel pump and clamp it down.
Step 17: Ground Electric Choke Wiring
Grab the black ground wire supplied with your carburetor install kit and connect it to the lower negative terminal of the choke housing. Ground the electric choke wiring by removing one of the choke housing bolts and connecting the opposite end of the wire to the bolt and tightening it down. If your engine had an automatic choke previously, simply connect the existing power lead to the positive upper terminal marked with a plus sign on the choke housing.
If you need to make a new connection, run the supplied power lead back to the fuse box under the dashboard and connect it to a switched 12 volt power source. This source will typically be marked ACC for accessory. If you're not sure, you can use a test light to gauge power at each fuse when you turn the ignition key.
Pro Tip:Do not hook the power lead up to the positive side of the coil since it will rob the engine of power. Do not attach it to the alternator either.
Step 18: Install Base Plate Gasket
Install the baseplate gasket on the top of your carburetor and then use the supplied mounting studs to screw in your new air filter. You'll have to crank your engine 5 to 15 seconds for fuel to reach the carburetor and your engine should fire right up!
Congratulations! You're all done.
Make the Most of Your Mustang Carburetor Replacement
Installing a Mustang electric choke carburetor is a great way to improve the performance and reliability of your pony car. It eliminates the need for a manual choke and provides smoother cold starts, which can be a big relief during those chilly mornings.
With proper installation, a Mustang electric choke carburetor can significantly improve your daily driving experience, making it a worthwhile investment for any Mustang owner. If you're still looking for the right carburetor for your Mustang, be sure to check out our full range of brands and style options to help take your build to the next level.