1976 M151-A2 Zenith Carburetor

Pumping the accelerator pedal, gas pedal, does not add fuel into a Zenith carburetor on a M151 Army jeep. The fuel is only drawn into the carburetor because of the vacuum created by the up and down motion of the engine pistons be it during engine cranking (starting) or during running. There is no accelerator circuit on this Zenith carburetor so pumping the gas pedal is useless. But there is a Full speed and Main metering fuel circuit that will allow fuel to be added but only if the vacuum created by the up and down motion of the engines pistons pulls the fuel from the carburetor float bowl into the carburetor itself.