A motorcycle choke, also known as a choke valve or enrichener, is a device found in many carbureted motorcycles. It is used to modify the air-fuel mixture when starting a cold engine or when the engine is not running smoothly due to inadequate fuel flow. The choke restricts the airflow to the engine, creating a richer fuel mixture by increasing the proportion of fuel to air.
When an engine is cold, it requires a richer fuel mixture for proper combustion. The choke helps achieve this by reducing the amount of air entering the engine, increasing the fuel-to-air ratio. This richer mixture makes it easier for the engine to start and run smoothly until it reaches operating temperature.
Fuel-injected engines use sensors and electronic controls to automatically adjust the air-fuel mixture based on various parameters such as engine temperature and throttle position. These systems eliminate the need for a manual choke since they can automatically provide the optimal fuel mixture for starting and running the engine smoothly in different conditions.
In summary, the choke is a device used in carbureted motorcycles to enrich the fuel mixture for easier cold starts or when the engine is not running smoothly. However, with the advancement of fuel injection technology, many modern motorcycles no longer require a choke as the fuel mixture is automatically adjusted by electronic controls.