What usually causes a riding mower engine to stall frequently?

A dirty carburetor is often a primary cause of frequent stalling in a riding mower engine. The carburetor is responsible for mixing fuel and air to create the combustion mixture that powers the engine. When it becomes clogged or dirty, it cannot properly mix the air and fuel, leading to poor engine performance. This can result in stalling, as the engine may not receive enough fuel to maintain consistent operation.

Factors such as low oil levels, a faulty spark plug, or overheating can contribute to engine problems but do not specifically point to the carburetor's role in the stalling. For instance, low oil levels could lead to engine damage but may not directly cause stalls as frequently as a dirty carburetor would. Similarly, while a faulty spark plug can disrupt ignition, it does not affect the fuel-air mixture like a dirty carburetor does. Overheating can also lead to engine shutdowns but typically occurs as a result of other issues, rather than being a direct cause of frequent stalling. Therefore, addressing a dirty carburetor is crucial for resolving the stalling issue in a riding mower engine.