What is the primary role of the choke in an engine?

The primary role of the choke in an engine is to enrich the air/fuel mixture. When starting a cold engine, the choke limits the amount of air that enters the carburetor. This results in a richer mixture of fuel to air being sent into the engine, which is essential for starting the engine efficiently when it is cold. A richer mixture improves combustion in cold conditions, aiding in a smoother and more reliable engine start.

Once the engine warms up, the choke is typically disengaged, allowing normal air intake and a balanced air/fuel mix, which is necessary for optimal engine performance. The choke's function is particularly important in small engines commonly found in outdoor power equipment, where starting under varying temperature conditions is a regular occurrence.