FACTS ABOUT CARBURETORS
- A carburetor mixes fuel with air and meters the mixture.
- Atmospheric pressure forces air through the carburetor into the lower pressure area of the combustion chamber.
- A venturi increases the velocity of air passing through a carburetor and creates a low pressure area.
- The fuel-air mixture must be vaporized before introduction into the combustion chamber.
- The carburetor systems are: Float System, Idle or Low Speed System, Main Metering System, Power System, Accelerating System, and Choke System.
- The Float System controls the level and supply of fuel.
- The Idle or Low Speed System furnishes the proper mixture for the engine idle, light load and slow speeds.
- The Main Metering System controls the fuel mixture from the transfer range to full throttle.
- The Power System provides a richer mixture for maximum power and high speed operation.
- The Accelerating System controls a small amount of fuel discharged into the air stream for sudden acceleration.
- The Choke System delivers additional fuel to the manifold for cold engine starting.
This article was adapted from an AEA Technical Training Manual article published in 1955.