How does a manual choke operate?

A manual choke operates by allowing the engine operator to manually control the air intake to the engine's carburetor, which effectively modifies the air-fuel mixture. This is typically done through a lever or pull-cable system, giving the operator the ability to enrich the mixture, particularly during cold starts, by reducing the amount of air entering the engine.

When the choke is engaged, it closes off some of the air intake, resulting in a richer mixture of fuel and air that helps the engine to start and run smoothly when it is cold. Once the engine warms up, the operator can disengage the choke to return to a normal air-fuel ratio. Understanding how and when to operate the manual choke is crucial for optimal engine performance, especially under varying conditions.

The other options suggest automatic or electronic controls, which do not apply to manual chokes that require direct input from the operator. This difference highlights the hands-on aspect of using a manual choke compared to automatic or sensor-driven systems.