Study guide
The function of a carburetor (on a spark ignition system) is to atomize the fuel and mix the atomized fuel in proper proportions with the air flowing to the engine intake port or intake manifold. Carburetors vary greatly in design but function on the same principle of mixing fuel and air.
Venturi priniciple-basically states that as air/fluid is passed through a constricted opening, the velocity is increased as well as a decrease in pressure on the down-flow side of the "ventruri".
Fuel and Air mixture
14.7:1 (fourteen point seven to one)
Which means that 15 parts of air to 1 part of fuel. This number fluctuates based upon engine load, temperature, acceleration and carburetor type.
Starting, cold weather 7:1
Accelerating 9:1
Idling (no load) 11:1
Part open throttle 14.7:1
Full load, open throttle 13:1
14.7:1 (fourteen point seven to one)
Which means that 15 parts of air to 1 part of fuel. This number fluctuates based upon engine load, temperature, acceleration and carburetor type.
Starting, cold weather 7:1
Accelerating 9:1
Idling (no load) 11:1
Part open throttle 14.7:1
Full load, open throttle 13:1