California DMV Motorcycle Knowledge Test (M1)Motorcycle Controls and Basic ManeuversEasy
A rider is preparing to start their motorcycle after it has been sitting overnight in cold weather. What is the primary reason for using the choke?
- ATo decrease the engine's idle speed to prevent over-revving.
- BTo lean out the fuel-air mixture for better fuel efficiency.
- CTo increase the engine's idle speed for faster warm-up.
- DTo create a richer fuel-air mixture, aiding in cold starting.
Show answer & explanationAnswer & explanation
Correct answer: D. To create a richer fuel-air mixture, aiding in cold starting.
The choke system restricts airflow into the carburetor, which creates a richer fuel-air mixture. This richer mixture is necessary for a cold engine to start and run smoothly until it reaches operating temperature.
Why the other options are wrong
- A. The choke typically increases, not decreases, idle speed as a secondary effect of enriching the mixture.
- B. Leaning out the mixture would make it harder, not easier, for a cold engine to start.
- C. While the choke can increase idle speed, its primary function is to enrich the mixture, not just increase RPM.
Choke System
A device on carbureted engines used to provide a richer fuel-air mixture for starting a cold engine.
- Restricts airflow into the carburetor.
- Increases the proportion of fuel to air.
- Used only for cold starts and warm-up.
- Should be disengaged as the engine warms.
Memory trick: Cold start needs rich mix, choke helps it tick.