Complete Guide: How to Rebuild Edelbrock 1406 and 1405 Carburetors

Rebuilding an Edelbrock 1406 or 1405 carburetor might seem intimidating at first, but with the right tools, a quality rebuild kit, and this comprehensive guide, it's a project that most DIY mechanics can tackle successfully. These performance carburetors are popular choices for street rods, muscle cars, and marine applications, known for their electric choke, annular boosters, and excellent throttle response.

In this guide, we'll walk you through the entire rebuild process, from disassembly to reassembly, highlighting common pitfalls and professional tips along the way. Whether you're dealing with a rough idle, poor acceleration, or just performing preventative maintenance, this tutorial will help you get your Edelbrock carburetor back to peak performance.

🛒 Don't Want to Rebuild? Get a Brand-New Replacement

Rebuilding takes hours and can still leave you with worn castings and old components. If you'd rather drop in a fresh, fully-assembled performer carburetor, iFJF offers direct Edelbrock-compatible replacements at a fraction of the OEM price:

⚡ 1406 — Electric Choke

600 CFM | 4-Barrel Square Bore | Electric Choke | $239.99

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🔧 1405 — Manual Choke

600 CFM | 4-Barrel Square Bore | Manual Choke | $239.99

Shop 1405 →

Already have an iFJF carburetor? This rebuild guide works for our replacements too — the internal design is fully compatible with Edelbrock kits #1487 (1406) and #1486 (1405).

When Should You Rebuild Your Carburetor?

Recognizing the signs that your Edelbrock carburetor needs a rebuild can save you from more expensive repairs down the road. Here are the most common indicators:

Symptoms That Indicate a Need for Rebuild

• Rough or unstable idle: If your engine idles roughly or stalls frequently
• Hesitation or stumbling: When accelerating from a stop or under load
• Poor fuel economy: Noticeably decreased miles per gallon
• Black smoke from exhaust: Indicates a rich fuel mixture
• Flooding: Fuel leaking from the carburetor or strong gas smell
• Age and contamination: If the carburetor has been sitting for years with old fuel

Essential Tools and Parts Needed

Before starting the rebuild process, gather all necessary tools and parts. Having everything on hand will make the process smoother and prevent frustrating interruptions.

Required Tools

• Socket set and wrenches: Metric and SAE, depending on your application
• Screwdrivers: Phillips and flathead in various sizes
• Carburetor cleaner: Aerosol type for cleaning passages
• Compressed air: For blowing out passages (optional but helpful)
• Small pick or pin: For removing pins and clips
• Torque wrench: For proper bolt tightening
• Clean rags or shop towels: Plenty of them
• Parts tray or magnetic mat: To organize small parts
• Camera or smartphone: Take photos before disassembly for reference

Parts Included in Rebuild Kit

• Gaskets: All necessary gaskets for top and bottom covers
• Metering rods and springs: Color-coded for different vacuum pressures
• Jets: Primary and secondary (check your model's specifications)
• Accelerator pump: Diaphragm and spring
• Float: Needle and seat assembly
• Various clips and pins: For linkages and controls
• Idle mixture screws: Often included (check kit contents)

Step-by-Step Rebuild Process

Now let's dive into the actual rebuild process. Work on a clean, well-lit surface, and organize your parts as you remove them. Remember: patience and attention to detail are key to a successful rebuild.

Step 1: Remove the Carburetor from the Vehicle

If the carburetor is still installed on the engine:

1. Disconnect the negative battery terminal
2. Remove the air cleaner assembly
3. Label and disconnect all vacuum lines, fuel lines, and electrical connections
4. Unbolt the carburetor from the intake manifold
5. Carefully lift the carburetor off, noting the placement of any spacers or gaskets

Step 2: Initial Disassembly - Top Cover Removal

Start by removing the accelerator pump linkage:

1. Locate the small lever on the accelerator pump
2. Unscrew the linkage from the side using a suitable tool
3. This will give you freedom to move the linkage down and over to release the S-clip
4. Once the S-clip is released, set it aside safely (these are easy to lose!)

With the linkages removed, you can now access the top bolts:

1. Remove the top housing bolts
2. Pro Tip: Smart mechanics remove the metering valves along with these bolts - this gives you better access and prevents losing small parts
3. Lift the top cover off carefully

Step 3: Remove the Floats

The floats control fuel level in the bowl. Here's how to remove them:

1. Locate the float pivot pin
2. Use a small pin or pick to push the pin out through the small hole
3. Lift the floats out of the carburetor body
4. Inspect the needle and seat assembly - replace if worn or damaged
5. Replace the gasket at this time

Step 4: Remove Metering Rods

Metering rods control fuel flow based on engine vacuum. Although they should have been removed earlier with the top bolts, let's examine them now:

1. Each metering rod consists of: the rod itself, a pin, a clip, a spring, and a cap
2. The vacuum pulls the rod up and down based on spring pressure
3. Springs are color-coded for different vacuum pressures - do not mix them up!
4. Note the orientation and location of each rod for reassembly

Step 5: Access and Remove Jets

Jets control the amount of fuel delivered. You'll find:

1. Primary jets: Located in the front (easier to access)
2. Secondary jets: Located in the rear (sometimes difficult to access)

If a jet is stripped (a common problem), you may need to:

1. Use an easy-out or left-hand drill bit to remove the damaged jet
2. Drill out the damaged jet carefully
3. Retap the threads using the correct tap size
4. Install a new jet

Step 6: Remove Remaining Components

Continue disassembly by removing:

1. Accelerator pump and spring: Pull these out from the top
2. Electric choke (if equipped): Remove the screws and gasket
3. Idle set screws: Remove from the front of the carburetor
4. Check ball and weight: Some models have a spring, weight, and ball assembly in the bottom - remove carefully

Step 7: Clean All Components

Proper cleaning is critical for a successful rebuild:

1. Visual inspection: Look for gum, varnish, and debris in all passages
2. Carburetor cleaner: Spray all passages thoroughly
3. DIY hot tank: For heavily contaminated carburetors, a homemade hot tank solution can work wonders (use proper safety precautions!)
4. Compressed air: Blow out all passages to ensure they're clear
5. Avoid soaking gaskets: Remove all old gaskets before cleaning - they can swell and clog passages

Step 8: Reassembly - Bottom Up

Reassembly is essentially the reverse of disassembly, but with new parts from your kit:

Install new jets:

1. Hand-tighten primary and secondary jets carefully
2. Don't over-tighten - aluminum threads strip easily

Install check ball, weight, and fuel discharge nozzles:

1. Follow the sequence: check ball first, then weight, then discharge nozzle
2. Ensure they're seated properly

Install new gaskets:

1. Use only gaskets from your rebuild kit
2. Ensure proper alignment - misaligned gaskets cause vacuum leaks

Step 9: Reinstall Floats and Metering Rods

1. Drop the new floats in with the tab positioned correctly
2. Insert the pivot pin
3. Install new metering rods with the correct springs (remember, color-coded!)
4. Ensure smooth movement of metering rods - they should move freely with vacuum application

Step 10: Reinstall Top Cover

1. Place the new gasket on the top cover
2. Carefully lower the top cover onto the carburetor body
3. Install bolts with metering valves (if removed separately)
4. Tighten in a crisscross pattern to avoid warping
5. Don't over-tighten - snug is sufficient

Step 11: Reconnect Linkages

1. Reattach the accelerator pump to the linkage
2. Install the S-clip that holds the accelerator pump linkage
3. Reconnect all external linkages
4. Install the bracket with screw

Step 12: Install Electric Choke (1406 Models)

1. Locate the hole in the upper right of the carburetor
2. Line up the choke plate indent with this hole
3. The electric choke works by heating/cooling to adjust choke position
4. Hook up the linkage and secure with the provided clip
5. Test choke flap movement manually to ensure smooth operation

Step 13: Final Assembly and Testing

1. Reinstall idle set screws in the front
2. Double-check all linkages are connected properly
3. Use a torque wrench to tighten all bolts to specification (typically 3-5 ft-lbs for small carburetor bolts)
4. Make one more pass around the entire carburetor to ensure even tightening

Common Issues and Troubleshooting

Even with careful rebuilding, you might encounter some issues. Here are common problems and their solutions:

Problem: Engine Won't Start After Rebuild

Possible causes:

• Float level set incorrectly - adjust to specification
• Accelerator pump not priming - work the throttle several times
• Choke not closing (cold start) - check choke operation
• Vacuum leaks - check all gaskets and connections

Problem: Rough Idle

Possible causes:

• Idle mixture screws not adjusted - turn in until lightly seated, then back out 1.5-2 turns as starting point
• Vacuum leak at base gasket - spray carburetor cleaner around base while running; if RPM changes, you have a leak
• Incorrect float level - check and adjust
• Clogged idle passages - remove and clean thoroughly

Problem: Hesitation or Stumble on Acceleration

Possible causes:

• Accelerator pump not functioning - check pump diaphragm and linkage
• Incorrect metering rod springs - ensure correct color-coded springs are installed
• Jet size too small - may need to go up one size
• Weak fuel pump - check fuel pressure (should be 5.5-7 psi for Edelbrock carbs)

Problem: Flooding or Leaking Fuel

Possible causes:

• Float level too high - adjust float level
• Needle and seat not sealing - replace needle and seat
• Worn float - replace float (should be fuel-free, not saturated)
• Excessive fuel pressure - install fuel pressure regulator

Pro Tips and Best Practices

These tips come from experienced mechanics who rebuild carburetors regularly. Following these practices will improve your chances of success:

Organization is Key

• Use a parts tray with compartments to organize small parts
• Take photos before disassembly from multiple angles
• Keep screws and bolts with their respective components
• Work on a clean, well-lit bench

Don't Rush the Cleaning

• Thorough cleaning is more important than speed
• Use a brush to scrub all surfaces
• Blow out ALL passages with compressed air
• Inspect visually with a flashlight to ensure passages are clear

Use Quality Parts

• Buy rebuild kits from reputable sources
• Avoid ultra-cheap kits with questionable quality
• Consider OEM Edelbrock parts for critical components
• Replace all gaskets, even if they look okay - old gaskets can fail prematurely

Adjustment After Rebuild

• Set initial timing before adjusting carburetor
• Adjust idle mixture screws for smoothest idle
• Set idle speed to specification (typically 600-800 RPM for most V8s)
• Check float level with car on level surface
• Test drive and recheck adjustments after engine reaches operating temperature

Conclusion

Rebuilding an Edelbrock 1406 or 1405 carburetor is a rewarding DIY project that can save you hundreds of dollars compared to buying a new carburetor or paying a shop to rebuild it. While it requires patience, attention to detail, and some mechanical aptitude, most enthusiasts can successfully complete this project in an afternoon.

Remember these key takeaways:

• Take your time: Rushing leads to mistakes that can be costly
• Stay organized: Small parts are easy to lose or install incorrectly
• Clean thoroughly: Contamination is the enemy of carburetors
• Use quality parts: A $20 rebuild kit isn't worth the frustration if it fails prematurely
• Double-check your work: One missed step can cause poor performance or engine damage

If you encounter problems beyond your comfort level, don't hesitate to consult a professional. Sometimes a second pair of eyes or access to specialized tools (like a carburetor flow bench) can make the difference between a successful rebuild and a frustrating experience.

We hope this guide has been helpful in your carburetor rebuild project. If you have questions or want to share your experience, feel free to reach out. And remember, regular maintenance and using quality fuel can extend the time between rebuilds significantly.