Model Engine Company of America
How to hook up the Kavan Carburetor

The large type KAVAN carburetor uses a pressure release to stabilize the fuel tank pressure when you transition from high speed to idle.

At high speed the fuel tank pressure builds up and then when the engine is throttled back to an idle, the input pressure from the exhaust is reduced. During this period while the pressure is stabilizing, the idle mixture tends to be rich and leans out slightly as the pressure reduces.

Configure the fuel tank with 3 lines. Two vent and one pick up. Connect the fuel inlet to the klunk line (pick up line) in the tank and the pressure release line to one of the vent lines.

Hook the other vent line to your muffler pressure.

A good starting point for the main needle is about 4 to 5 turns out. Turn the main needle in, clockwise, until it stops. DO NOT FORCE IT. You could place a piece of fuel tubing on the fuel inlet nipple and blow through it and screw it in until the flow stops, be sure the throttle barrel is in the full open position. Now unscrew the main needle 4 to 5 turns.

Next set the idle air bleed. Close the carburetor until you reach the lowest speed possible without the engine dying. Turn the air bleed screw in to richen the mixture and out to lean it. In restricts the additional air being bleed into the carburetor..

The barrel stop screw does just that. It stops the barrel from closing completely and may need to be unscrewed slightly to obtain a low enough idle.

Click here to read general information on tuning a carburetor.

The KAVAN carburetor is also made so you can adjust the mid range mixture. THIS PROBABLY DOES NOT NEED TO BE DONE.

By loosening the spray bar lock screws and rotating the spraybar SLIGHTLY you can affect the mid range mixture. You may need to adjust the high and low speed setting if you mess with this.

The above information is provided as a guide. Since MECOA/K&B has no way of determining the ability of the individual using and understanding this information, we assume absolutely NO RESPONSIBILITY for any damage to person or property from the use of this information.

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