What is the typical cause of engine roughness during taxi as related to fuel system issues?

Engine roughness during taxi can often be attributed to water contamination in the fuel system. Water in the fuel can disrupt the combustion process, leading to uneven power delivery and rough engine operation. When water enters the combustion chamber, it can prevent fuel from igniting properly, thus causing misfires or rough running conditions, especially at low RPMs during taxi.

Maintaining fuel quality is crucial for the smooth operation of aircraft engines. Contamination can occur from various sources such as condensation in fuel tanks, improper storage, or refueling practices. Identifying and addressing water contamination is essential not only for ensuring engine performance but also for preventing potential damage to engine components over time.