What might happen when starting a turbojet engine with a fuel/air mixture that is set too rich?

Starting a turbojet engine with a fuel/air mixture that is set too rich can lead to a hot start condition. This occurs when there is an excessive amount of fuel compared to air in the combustion chamber, resulting in incomplete combustion. The surplus fuel does not burn efficiently, leading to higher than normal temperatures.

As the engine attempts to ignite this rich mixture, it can produce a lot of heat, which, if unchecked, can cause the temperature within the engine to exceed its safe operating limits. The term "hot start" specifically refers to this scenario where the temperature climbs dangerously high, potentially damaging engine components if the situation is not corrected quickly.

In contrast, the engine may not necessarily stall, fail to start at all, or produce excessive smoke in all scenarios where a rich mixture is applied, depending on various factors such as engine design and operating conditions. Therefore, the phenomenon of a hot start is the most accurate implication of starting a turbojet engine with an excessively rich fuel/air mixture.