Oxford Reciprocating Engines Practice Test

An excessively rich mixture refers to a situation where there is too much fuel in relation to the amount of air in the combustion chamber. This imbalance can lead to several distinct symptoms that affect engine performance.

One of the primary symptoms is a loss of power. This occurs because an overly rich mixture does not burn as efficiently as a properly balanced mixture. The excess fuel can lead to incomplete combustion, resulting in lower energy being produced, which ultimately manifests as a reduction in power output from the engine.

In the case of cylinder head temperature, an excessively rich mixture often results in a drop in temperature. This happens because the increased fuel cools the combustion process. More fuel than necessary absorbs heat during combustion, preventing the cylinder head from reaching optimal operating temperatures. Consequently, the engine may operate cooler than intended due to this rich condition.

Understanding these symptoms helps in diagnosing engine issues related to fuel mixture and in making necessary adjustments to ensure proper engine performance.