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The carburetors used on today's gasoline model engines are very easy to adjust and pretty high tech in design. How they work... the carburetor is equipped with a diaphragm pump. This pump is activated as soon as the engine is started by means of the negative and positive pulse that is generated in the crank case. This pulse is routed through the back of the intake manifold and into one of the active small holes located on the back side of the carburetor. Proper orientation is extremely important to prevent any blockage of the tiny hole. For instance, if the carburetor or gaskets are installed incorrectly (ie. upside down) it would result in an engine that may start an idle but fail to make the transition to high speed. This pump system is one of the main reasons that these engines are so reliable. Fuel is drawn into the carburetor and does not rely on gravity or other pressure. This means that fuel tank location is not as critical, and once the carburetor has been primed the pump will do the rest.

Each carburetor is equipped with two adjustable fuel metering needle valves, one responsible for low to mid range, and one responsible for high speed fuel metering. The third and final adjustment enables the closing position of the throttle plate. This adjustment will determine the actual low speed idle. Certain carburetors are equipped with a fuel primer bulb which can be pressed/squeezed to draw fuel from the tank and prime the carburetor. Some carburetors are equipped with a choke that can also be used in starting a cold engine. Some high performance carburetors have neither of the two, which can still easily be choked by manually inserting your finger into the carb opening while pull starting which will cause fuel to be drawn to the carburetor.

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Walbro Carb Theory

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Big Bore for Stock 25-30cc

Our Price: $39.95

We found this carb a few years ago and used it on our stock and mid-mod engines. You can gain 3-5 mph by simply bolting it on.

WT 257 Zenoah 23-25cc

Our Price: $49.95

The Big Bore carburetor of choice for performance Zenoah engines. Simply bolt this to your Zenoah engine and add even more horsepower.

Zenoah G260 Replacement

Our Price: $59.51

Direct replacement for Zenoah G260 25.4 cc engines.

Zenoah G230 Replacement

Our Price: $44.95

Direct replacement for Zenoah G230RC 23 cc engines.

Air Cleaner / Diffuser

Our Price: $9.95

Air Cleaner / Diffuser for use with WT644 carb, assembled and ready to install.
Recommended for use with engined with choke, fits Enforcer or Zenoah stacks.

Snozzler II

Our Price: $18.95

Introducing the new "Snozzler II" designed for Big Bore carbs that are equipted with a choke. The Snozzler II is almost manditory for all boats that operate without a hatch cover and the carb is exposed. This will help keep the water spray out and also help prevent piston rod bending from ingesting that big gulp of water associated with overturning at high engine rpm's. The Snozzler will work with most Walbro type carburetors.

Velocity Stack (Aluminum)

Our Price: $18.95

Enhance your �Big Bore� carb with our Velocity Stacks. They really work! Not just for looks. Choke must be removed for use. Can be polished as shown.

Velocity Stack (Composite)

Our Price: $9.95

Enhance your �Big Bore� carb with our Velocity Stacks. They really work! Not just for looks. Choke must be removed for use.

CNC Choke Plate Adapter

Our Price: $4.95

For use with Velocity Stacks on carbs with chokes to provide proper spacing to clear the choke butterfly.

Choke Lever for Zenoah G260

Our Price: $10.95

CNC machined choke lever fits Zenoah G260 carburetor and others with .187 shaft diameter. Also available in anodized colors.