Manifold Intake Adapters, Inlets & Joints
About Manifold Intake Adapters, Inlets & Joints
An intake manifold, flange or adapter joins a carburetor or throttle body to the cylinder head and carries the air-fuel charge into the engine. Riders replace them when rubber joints harden and crack, when a flange warps or leaks and lets in unmetered air, or when a larger, ported manifold is part of an engine upgrade.
Most listings here are for Harley-Davidson engines, named by family: Evolution, Big Twin, Twin Cam, Sportster and M8. Manifolds are matched to what bolts to them. An HSR manifold and a CV manifold suit different carburetor styles, and an EFI manifold such as a 55 mm M8 unit is sized for a throttle body. Sensor holes vary, so check whether your intake needs a port. The category also lists a reed valve system for Honda CR dirt bikes and a few adapters for other parts such as brake lines. Match engine, model and year, or use the Ride Finder at the top of the page.
Brands here include Colony, HardDrive, Mikuni, Drag Specialties and S&S Cycle. A manifold joint needs fresh seals, so see Gaskets, Seals & O-Rings. The carburetors that bolt to it are under Carburetors, and the whole group is Air Intake & Fuel Delivery.
FAQs on intake manifolds and adapters
What are the signs of an intake manifold air leak?
A leak lets in extra air that the carburetor or fuel system is not measuring. Typical signs are a high or hunting idle, surging, hesitation, popping on deceleration and a lean-running engine. Cracked rubber joints and loose or flattened seals are the usual causes, so check those first.
What is the difference between an HSR and a CV manifold?
They are made for different carburetor designs. An HSR-style manifold suits an HSR carburetor, and a CV manifold suits a constant velocity carburetor, and the flange shape and bore are not interchangeable. Check the carburetor on your bike and choose the manifold listed for it.
Do I need new O-rings or gaskets when replacing a manifold?
Yes. Use new seals at both ends of the manifold, at the cylinder head and at the carburetor or throttle body, because old ones harden and can leak air. Follow the service manual for the sealing method and the tightening order for your engine.
Does a larger intake manifold add power by itself?
Not on its own. A bigger or ported manifold helps only when the carburetor or throttle body, air filter, exhaust and engine can use the extra airflow, and it usually needs a tune to match. Follow the manufacturer's notes for supported combinations rather than mixing parts at random.
Can I use a manifold from a different model?
Usually not. Port shape, bolt pattern, bore and sensor provisions differ between engine families and model years. Use the engine family and years named in the listing, or pick your bike in the Ride Finder to narrow the list to parts made for it.
