Starting an engine in cold weather is somewhat difficult. Choking device makes engine starting easier. The choke valve is butterfly valve, similar to the throttle valve. This valve is situated between the air intake and the venture. At the time of starting, the choke valve is turned to close almost the inlet passage. This is called choking. Then, during suction stroke, a greater depression is created in the inlet passage and is felt on the fuel jet which is situated at the throat of the venture. This causes more fuel to be ejected by the fuel jet. Choking restricts airflow and provides an over supply of fuel. It should be remembered that only the lighter fractions of the supplied fuel evaporate at lower temperatures and form a combustible mixture in the cylinder. During initial cranking of the engine, the choke valve is almost completely closed. Once the engine fires consistently, the choke valve is opened slightly to keep the engine running. As the engine warms up to it...
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