What is the action of a float-type carburetor accelerating system when the throttle is opened quickly?

• A. Reduces fuel to prevent flooding.
• B. Supplies extra fuel during sudden increases in power.
• C. Maintains a constant fuel supply regardless of throttle.
• D. Shuts off fuel momentarily.

Answer: (B)

When you open the throttle quickly, the air rushes into the engine much faster than the normal fuel metering can keep up with. The accelerating system in a float-type carburetor is designed to handle this momentary mismatch by delivering a quick burst of fuel from the float bowl through a discharge nozzle into the incoming air. This extra fuel enriches the mixture just as the throttle opens, helping the engine respond smoothly and preventing a hesitation or bog that would occur if the mixture stayed lean.

After that initial burst, the engine returns to the normal fuel supply guided by the main jets and metering system. The other options don’t fit because reducing fuel to prevent flooding isn’t the role of the accelerating system, maintaining a constant fuel supply ignores the need for a momentary enrichment during sudden acceleration, and shutting off fuel momentarily would cause a lean spike, not a smooth acceleration.