Remove the spark plug from the engine
Inspect the spark plug for cracks, heavy wear, or damaged electrodes
Wipe off loose dirt and oil with a clean rag
Use a wire brush or spark plug cleaning tool to remove carbon buildup from the tip and threads
Spray the plug with brake cleaner or carburetor cleaner if needed
Clean the electrode gap gently without bending the metal parts
Check the gap with a feeler gauge and adjust if necessary
Dry the spark plug completely
Reinstall the spark plug and tighten it to the correct torque specification