What do you need to know about Keihin carburetors?

What do you need to know about Keihin carburetors?

Rollers on throttle valves and progressive linkage for smooth operation and control. Equipped with accelerator pump for rapid acceleration without flat spots. Designed for easy installations on popular motorcycles. Easy jetting which can be done at track side.

Where to get replacement parts for Keihin cvk40?

While most of the following information applies to all CV carbs, and to some extent all carb types, this article is specific to the Keihin CVK40 found on many Kawasaki motorcycles (KLR’s and Vulcans) along with some Harleys. If you need replacement parts you’d be well advised to get them from your local Harley Davidson outlet.

What happens when diaphragm valve is raised on Keihin cvk-40?

As the diaphragm valve is raised from the venturi depression (lowest pressure area), the needle is pulled further out of the needle jet, exposing a thinner portion of the needle taper which allows even more fuel to rise into the venturi to meet the increased engine demand.

How is the bottom chamber of a cvk-40 carburetor separated?

The top chamber is separated from the BOTTOM chamber by the rubber diaphragm. The bottom chamber is open to atmospheric pressure from the airbox by the crescent shaped casting on the top of the venturi.

How does the carburetor work on a Keihin cvk-40?

The bottom chamber is open to atmospheric pressure from the airbox by the crescent shaped casting on the top of the venturi. When the vacuum in the top chamber rises sufficiently, the constant ambient pressure of the lower chamber, helps the diaphragm valve overcome the downward force of the diaphragm spring, and it rises from the venturi.

Is the cvk40 a bleed or constant vacuum carb?

They will be less expensive than ordering through your Kawasaki dealer and, in most cases they will be ‘in stock’. The CVK40 is technically a bleed type carb, with a variable venturi that’s controlled by constant velocity (CV). It’s also known as Constant Depression or Constant Vacuum. The 40 in the name represents a 40 mm venturi exit diameter.

What’s the best way to tune a CVK carburetor?

Gently screw the pilot or idle mixture screw until it just begins to bottom out. Be careful not to damage the carb by over-tightening. Once the screw is tightened, back it out of the carb by one and 7/8 turns to the factory position.

What does the 40 mm Venturi mean on a cvk40?

It’s also known as Constant Depression or Constant Vacuum. The 40 in the name represents a 40 mm venturi exit diameter. Wonder why ‘K’awasaki added the K…? Most carbs have a one piece needle jet. On the CVK40 it consists of a collar and what Kawasaki calls a holder. Most 4-strokes have pin holes along the length of this brass jet.

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