What should be done if a spark plug shows signs of fouling?

When a spark plug shows signs of fouling, addressing it by replacing or cleaning the spark plug as needed is essential for optimum engine performance. Fouling occurs when unwanted deposits accumulate on the spark plug's surface, which can result from various factors like improper fuel mixture, excessive oil consumption, or poor combustion efficiency.

Cleaning the fouled spark plug can sometimes restore its functionality by removing carbon deposits or oil buildup. In cases where the fouling is severe or the plug is damaged, replacing it is the best option to ensure reliable ignition and efficient engine operation. By taking this action, you are directly addressing the symptoms of the problem and promoting a clean combustion environment, which is crucial for overall engine health.

While inspecting the fuel system or modifying engine parameters like idle speed and ignition timing might be necessary steps to take after addressing the foul plug, they don’t directly resolve the immediate issue of a fouled spark plug. Cleaning or replacing the plug is the most direct and effective response.