As the piston approaches top-dead center, the mixture is ignited by the spark plug, and when the fuel vaporizes in the cylinder, the air and fuel mixture is cooled. 由于活塞的办法顶端死中心，混合物点燃的火花塞，当燃油蒸发在汽缸内的空气和燃料混合物冷却。
The idle system supplies a very rich mixture to start with. 怠速系统提供很浓的可燃混合气供起动使用。
The ignition system provides high-voltage electric parks that ignite, or set fire to, the charges of air-fuel mixture in the engine combustion chambers. 点火装置产生高压电火花，从而使发动机燃烧室中的可燃混合气起燃。
