What is the primary purpose of the ignition system in a four-stroke engine?

The primary purpose of the ignition system in a four-stroke engine is to ensure ignition occurs at the correct timing. This timing is crucial for the engine's performance and efficiency. Proper timing allows the air-fuel mixture to ignite at exactly the right moment in the engine cycle, which maximizes power output and minimizes emissions. An advanced or retarded ignition timing can lead to poor engine performance, knocking, or backfiring, highlighting the significance of precise timing in the ignition process.

The other options focus on different functions that are not directly related to the ignition system's primary role. Regulating engine temperature and cooling are managed by the engine's cooling system, while fuel efficiency is influenced by various factors in the engine's design and operation but not solely by the ignition system itself.