On a motorcycle, a choke is a device used to modify the air-fuel mixture entering the engine to facilitate starting and warm-up in cold conditions. The choke restricts the airflow into the carburetor, making the mixture richer (more fuel, less air) to aid combustion when the engine is cold.
When you activate the choke, it limits the amount of air entering the carburetor, resulting in a richer fuel mixture. This richer mixture helps the engine start and run smoothly during cold starts by providing more fuel for combustion.
Riding a motorcycle with the choke fully engaged for an extended period can result in an overly rich mixture, leading to poor performance, fouled spark plugs, excessive fuel consumption, and potential damage to the engine or catalytic converter.
Therefore, it's recommended to use the choke only when starting a cold engine and gradually reduce or turn it off as the engine warms up. Each motorcycle may have specific recommendations regarding choke usage, so it's best to consult the owner's manual for your specific motorcycle model.