How often should the spark plugs of a Levin be replaced?

[OMax]

The spark plugs of a Levin should be replaced every 40,000 kilometers. Methods to determine if the spark plugs are damaged: Remove the spark plugs and observe them. The condition of the spark plugs can be judged based on the following appearance colors. A normal spark plug has an insulator skirt and electrodes that appear gray-white, gray-yellow, or light brown. A properly functioning spark plug has a reddish-brown insulator skirt, with an electrode gap between 0.8-0.9mm, and no signs of electrode burning. If the spark plug has oil stains or deposits but is not damaged, it can continue to be used after cleaning off the oil and deposits. If the spark plug is severely damaged, with signs such as blistering at the top, black streaks, cracks, or melted electrodes, the cause of the damage should be identified. After troubleshooting, replace the spark plug with a new one. Additionally, if the spark plug appears black as if smoked, it indicates that the wrong heat range was selected for the spark plug, the air-fuel mixture is too rich, or there is oil leakage.