Intake Manifold | Honda CB350 / CL350 / SL350 K0
Replacement carburetor intake manifold for Honda CB350 K0–K5, CL350 K0–K5, and SL350 K0 motorcycles. Also known as carburetor boots, isolators, intake pipes, or carb flanges. These manifolds seal the joint between the carburetor body and the cylinder head intake port. Replaces OEM 16211-286-040.
Sold individually. Each motorcycle uses two intake manifolds — one per carburetor.
Choose Your Option
- OEM Honda (#6251): Genuine Honda intake manifold — original factory quality.
- Reproduction (#6252): A well-fitting, budget-friendly alternative that seals and fits properly.
Why You Need This
Intake manifolds are one of the most commonly overlooked wear items on vintage Honda twins. The original rubber hardens, shrinks, and cracks over decades of heat cycles. Even manifolds that look fine on the outside can be hardened enough to leak — they get dry and stop sealing properly. The result is an air leak between the carburetor and cylinder head that leads to tuning difficulties. Fresh intake manifolds restore a proper seal and are recommended any time the carburetors are removed for service.
Complete the update with stainless steel intake manifold clamps for a better running and better-looking bike.
Specifications
| Specification | Detail |
|---|
| Replaces OEM | 16211-286-040, 16229-369-306, 16229-286-000, 16229-369-000 |
| Fits Models | CB350 K0–K5 (1968–1973), CL350 K0–K5 (1968–1973), SL350 K0 (1969–1970) |
| Quantity | Sold individually — two required per motorcycle |
| Location | Between carburetor body and cylinder head intake port |
Does Not Fit
CB350F (four-cylinder): This manifold is for the CB350 twin only. The four-cylinder CB350F uses a completely different intake manifold.
SL350 K1 and K2: The SL350 K1 and K2 use a different carburetor and intake manifold. This part fits the SL350 K0 only.
Installation
Difficulty: Easy — no special tools required
These manifolds are designed for use with factory-style air filters that support the weight of the carburetor from the rear. The new manifold should sit nice and clean on the carburetor with a good, firm connection. If using pod air filters, fabricate a hanging support to hold the carburetors up and off the intake manifolds. Without rear support, the weight of the carburetors can stress and damage the manifolds over time. Do not over-tighten the manifold clamps — snug is sufficient.
Frequently Asked Questions
How do I know if my intake manifolds need replacing?
If your bike has been sitting for years, the manifolds almost certainly need replacing — the rubber hardens and shrinks even when the bike is not ridden. Even manifolds that look like they are in good shape are common culprits for air leaks and tuning problems.
What is the difference between the OEM and Reproduction options?
The OEM Honda manifold (#6251) is the original factory part. The Reproduction (#6252) is an aftermarket alternative that fits and seals properly at a lower price point. Both are sold individually.
Do I need new manifold clamps too?
The original clamps often work fine if they are not corroded or stripped. If yours are rusty or the screw is rounded out, we sell stainless steel replacement clamps with an anti-gouging guard that prevents the clamp screw from cutting into the manifold rubber.
Will this fit my SL350?
Only the SL350 K0 (1969–1970). The SL350 K1 and K2 switched to a different carburetor and intake manifold that is not compatible with this part.
Should I replace these while rebuilding my carburetors?
Yes. Any time the carburetors are off the bike for a rebuild, replace the intake manifolds. It takes no extra time and eliminates a common source of air leaks that can mask the results of a fresh carburetor rebuild.
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Last updated: March 2026
