What is the difference between a rich mixture and a lean mixture?

[LaPaige]

The difference between a rich mixture and a lean mixture is excessive fuel injection and insufficient fuel injection. The phenomena of rich and lean mixtures are introduced as follows: Phenomena of a rich mixture: Difficulty in starting the engine, insensitive acceleration, black smoke from the exhaust pipe accompanied by abnormal noise. After the engine is turned off, gasoline leaks from the throttle shaft, and the engine lacks power with increased fuel consumption. Phenomena of a lean mixture: The engine is hard to start, idle operation is unstable and prone to stalling, a feeling of insufficient power while driving, and in severe cases, the vehicle stops. When the engine is under no load, pressing the accelerator pedal does not easily increase the speed, the carburetor experiences backfiring, and the engine is prone to overheating.