- main metering circuit
- The cruising circuit or the high speed circuit. It supplies the correct air/fuel mixture to the engine during cruising and high-speed conditions. Also called main metering system
Dictionary of automotive terms. 2015.
Dictionary of automotive terms. 2015.
main-well tube — A perforated tube which extends from an air bleed in the top of the air horn down into the main well. Admits air from the air bleed into the main well to emulsify the fuel in the main well. Improves idle response and stability when the engine is… … Dictionary of automotive terms
metering signal — A (relative) vacuum signal generated by the pressure differential that occurs at the venturi. The strength of the metering signal determines how much fuel is pulled from the main circuit into the venturi. The smaller the venturi the greater the… … Dictionary of automotive terms
high-speed circuit — Main metering system … Dictionary of automotive terms
idle circuit — At idle and low speeds, the carburetor system supplies enough fuel to the engine to keep it running. When the vehicle gets up to speed (usually about 24 kph or 15 mph) the idle circuit kicks out of operation so that fuel is supplied by the main… … Dictionary of automotive terms
cruising circuit — The main carburetor metering system … Dictionary of automotive terms
emulsion tube — part of a fixed jet carburetor, in which air is introduced into the mixture through holes to help atomize it and correct excessive richness at higher engine speeds. A perforated tube which extends from an air bleed in the top of the air horn down … Dictionary of automotive terms
off-idle discharge ports — The holes that deliver fuel from the idle circuit during the transition from curb idle to the main metering circuit. Located just above the throttle plates. At curb idle, off idle ports function as an extra air bleed for further emulsification of … Dictionary of automotive terms
transfer ports — The holes that deliver fuel from the idle circuit during the transition from curb idle to the main metering circuit. Located just above the throttle plates. At curb idle, off idle ports function as an extra air bleed for further emulsification of … Dictionary of automotive terms
fixed idle-air bypass — Some Rochester Quadrajet carburetors have idle air passages from the air horn to a point just below the throttle plates. Extra air through these passages allows the throttle plates to be more closed at idle, reducing the signal applied to the… … Dictionary of automotive terms
nozzle drip — Air rushing by the venturi at idle can cause fuel to drip from the discharge nozzle for the main metering circuit … Dictionary of automotive terms