What is a common symptom of a clogged air filter in outdoor power equipment?

A clogged air filter in outdoor power equipment restricts the flow of air to the engine, which can lead to a rich fuel mixture. This can cause several issues, with difficulty starting the engine being one of the most common symptoms. When the engine does not receive enough air, it struggles to combust the fuel efficiently, resulting in hard starts or refusal to start at all.

The other choices do not accurately reflect the effects of a clogged air filter. Reduced fuel consumption typically occurs with efficient air-fuel mixtures, not when airflow is restricted. Increased engine speed is unlikely because the engine would struggle to perform optimally due to the insufficient air supply. Less vibration during operation is also not a symptom related to a clogged air filter; in fact, various engine issues can lead to increased vibration rather than a reduction. Thus, experiencing difficulty starting the engine is a clear and direct symptom of an air filter issue.