Definition
A subsystem within a float-type carburetor that delivers a brief, extra spray of fuel into the airstream when the throttle is opened rapidly, preventing the engine from hesitating or stumbling during sudden power increases.
Plain English
A small pump inside the carburetor that squirts in extra fuel the moment you push the throttle forward quickly, so the engine doesn't cough or briefly lose power.
Context Anchor
Seen in piston-engine fuel system and carburetor discussions, especially when explaining throttle response.
Derivation
From 'accelerate' (Latin accelerare, 'to hasten' or 'speed up'). The system is named for what it supports — the act of accelerating the engine — not for accelerating fuel itself.
Why Pilots Care
Without it the engine can stumble or backfire on rapid throttle advance, affecting takeoff and go-around safety.
Intuition Check
Do not think of the accelerator system as the throttle itself. The throttle asks for more power; the accelerator system briefly adds extra fuel to help the engine respond cleanly.
Example Sentence 1
When the pilot pushed the throttle forward for the go-around, the accelerator system delivered extra fuel to keep the engine from stumbling.
Example Sentence 2
During annual inspection the mechanic checked the accelerator system pump for proper operation.