When adjusting the mixture to be richer, what is a potential consequence?

Adjusting the mixture to be richer means increasing the amount of fuel relative to the amount of air in the combustion process. This can lead to incomplete combustion, which can significantly elevate engine temperatures, particularly in the combustion chamber. When there is more fuel than air, not all fuel can be effectively burned, resulting in unburnt fuel leading to higher exhaust temperatures.

While a richer mixture might temporarily provide more power (due to increased fuel availability), it generally results in less efficient combustion, which can create excess heat and lead to potential engine damage over time if not managed properly. In contrast, the other options such as improved fuel efficiency and decreased cylinder pressure are usually not associated with a richer mixture. Instead, a richer mixture often leads to greater fuel consumption without increasing power output in a corresponding manner.