The Honda CB450 / CL450 / CB500T intake design, like many of the Honda twins of the era, use an elaborate air filter setup involving air filters, a filter cover, cross over tube seals, specialty hardware, and more. These pieces have become extremely difficult to find and expensive over the years. Since new factory filters are no longer available for the CB450, our Common Motor angled pod filters are the best option for keeping the CV Keihin carburetors on your motorcycle running properly.
Parts and tools needed
Parts
(x2) Common Motor angle boot pod filters (one per carburetor)
(x2) hose-clamp style intake manifold clamps (recommended in the video)
Recommended condition item
Intake manifolds in good condition (if the existing manifolds are old/stiff)
Tools
Basic hand tools to remove seat/tank (for access, as shown)
Screwdrivers/nut drivers for clamps
Wrenches/sockets for factory air filter hardware and side covers
Zip ties (carburetor support method shown)
Optional alternatives mentioned: safety wire, or a custom support system
Why CB450 carburetors need added support with pod filters
The CB450 has a unique scenario where the carburetor's engagement into the intake manifold is very shallow. The factory design holds the carburetor at the front via the manifold and supports the rear via the factory airbox boot. Once the factory air filter assembly is removed, the carburetor is no longer supported at the rear and can “peel out” of the intake manifold while riding—especially over bumps—unless the installation includes added support.
Removing the CB450 factory air filter assembly
Step 1: Remove the special through-bolt and mounting screws
Locate the factory air filter setup after removing the side covers.
Identify the special bolt that passes through the assembly and threads into the battery box mounting area.
Remove that bolt and the remaining mounting screws securing the air filter assembly.
Step 2: Remove the factory filter covers and assembly
Remove the plastic air filter covers from the CB450 filter assemblies.
Remove the air filter assemblies completely to expose the carburetor inlets.
Preparing the CB450 for pod filters
Step 1: Verify intake manifolds are pliable and sealing
Inspect the intake manifolds for stiffness, cracking, or poor sealing surfaces.
Use manifolds that are new or at least pliable enough to seat the carburetor properly.
Why it matters: Poor manifold condition makes shallow engagement problems worse and increases the chance of the carburetor working loose.
Step 2: Replace factory manifold clamps with our Common Motor hose clamps
Remove the factory clamp from the intake manifold.
Seat the carburetor fully into the manifold.
Install a the thicker hose clamp style clamp for a stronger grip.
Clamp positioning tip:
Place the edge of the clamp right up against the edge of the manifold rubber so it sits flush at the end.
Why upgrade: Our CMC hose clamp style is preferred in the video because it can “bite down” more effectively and hold the carburetor more securely.
Step 3: Add a rear carburetor support strap (zip tie method shown)
After the carb is held better at the manifold, add a rear support so the carburetor does not bounce and flex on the manifold.
Plan a support that lifts slightly on the carburetor body to reduce weight and movement at the manifold.
The video demonstrates a quick support using zip ties:
Create a sling-like support around the carburetor area.
Route a zip tie through an available frame hole/mount point, then secure it so the carb is supported.
Adjust the support so it applies gentle lift/support without pulling the carburetor out of alignment.
Notes:
Zip ties are shown because they are common shop supplies and easy to illustrate.
Alternatives mentioned: safety wire or a more custom/clean support system such as a custom bracket.
Black zip ties are less noticeable than white ties (white ties were used so the support is visible on camera).
Installing the pod filters on a CB450
Step 1: Fit the pod and clock it downward
Slide the pod filter onto the carburetor inlet and wiggle it on until seated.
Clock the pod so the filter body faces downward (video method).
Step 2: Position the pod clamp for support clearance
Unlike other models where clamp screw placement is often on the bottom, the video places the pod clamp screw at the top on the CB450 so that it will not bite into the zip ties.
Rotate the pod clamp so the clamp screw is on top to create clearance for the carb support strap.
Rotate the clamp so it sits slightly back from straight-top center—described in the video as roughly a “1 o’clock” position when looking at the carb inlet like a clock face.
Step 3: Snug and finalize clamp tightness
Snug the pod clamp lightly at first while you finalize the support strap routing and tension.
Once the support is set, tighten the pod clamp until snug.
Avoid over-tightening; the goal is secure seating without deforming the boot.
Repeat the pod installation process on the other carburetor.
Reinstall side cover hardware
Reinstall the side cover mounting bolt that threads into the battery box.
The video notes that the washers previously used on that bolt are not needed in this configuration; reinstall the bolt and seat it fully as shown.
Reinstall the support washer and side cover.
Final checks before riding
Confirm each carburetor is fully seated in the intake manifold and the manifold clamp is tight and correctly positioned.
Confirm each pod filter boot is fully seated and the pod clamps are snug.
Confirm the carb support strap is supporting the front of the carburetor and reducing movement, not pulling the carb out of alignment.
Reinstall the tank and seat (if removed), then start the motorcycle and check for:
Intake leaks
Abnormal vibration causing carb movement
Unstable idle or hanging RPM
Jetting note: In the video we focus on mechanical installation and carb support. Pod filters can affect fueling and may require carburetor tuning. We recommend starting with the factory jetting and moving up or down based on the performance of the motorcycle.
Troubleshooting
The carburetor feels loose or moves up and down after installing pods
Confirm the intake manifold clamps were upgraded and tightened properly.
Verify the carburetor is fully seated in the manifold (shallow engagement makes partial seating risky).
Add or adjust the rear support strap to reduce flex and bouncing.
The pod clamp screw interferes with the support strap
Rotate the clamp so the screw is on top and offset to roughly “1 o’clock,” as shown in the video.
The carburetor keeps working its way out of the manifold
Recheck manifold condition (old/stiff manifolds can prevent proper seating).
Increase clamp grip with the beefier hose clamp and verify clamp placement flush to the manifold edge.
Improve the front support system (zip ties, safety wire, or a custom bracket) so the carb is supported.
FAQ
Why are pod filters considered the best replacement on a CB450?
Factory filters are not available new for this motorcycle, making pod filters the practical replacement.
Why does the CB450 need extra modifications compared to other models?
The CB450 carburetor engagement into the intake manifold is shallow, and the factory airbox boot supported the front of the carburetor. Removing the factory assembly removes that support, so stability must be added back in.
Can I use something other than zip ties for the support?
Yes. The video suggests safety wire or a custom support method. The requirement is to support the front of the carburetor so it does not flex and work loose.
Where should the pod clamp screw go on a CB450?
The clamp screw should be at the top (instead of the bottom) specifically to provide clearance for the added carb support.