Secondary Well is sucked into the Carburetor Seat

Posted by zjautopartsLee on April 8th, 2016

This is due to inertia, friction, and the viscosity of the gasoline flowing through the small jets. A simple jet carburetor cannot maintain the needed air/fuel ratio under varying suction levels and becomes too rich at high suction levels. If the Carburetor Needle is adjusted to make it work well at high speeds, it will be too lean at low speeds.

The zjautoparts, Model A carburetor is more complex than the earlier, simpler carburetors commonly in use. In addition to a main jet design, which results in an air/fuel mixture that becomes richer with increased engine speed, zjautoparts added some other functions.

The Cap Jet, Secondary Well, and Compensator Jet were added to provide a way to reduce the amount of gasoline provided to the engine as the suction (speed) increases, which is opposite of the Main Jet.

 These parts work by filling the Secondary Well with gasoline from the main bowl through the Compensator Jet when the engine is turned off or operating at low speeds.

 The Secondary well fills with gasoline and when the engine speed increases, all of the fuel in the Secondary Well is sucked into the Carburetor Seat throat through the Cap Jet.