What are the signs of a failing motorcycle spark plug?

[VonElisa]

Symptoms indicating the need to replace a faulty motorcycle spark plug include difficulty starting the engine, reduced power, excessive exhaust emissions, and increased fuel consumption. Severe spark plug damage may manifest as blistering, black streaks, cracking, or melted electrodes at the tip. Methods to determine if a spark plug is damaged: Remove the spark plug and observe its condition based on the following visual characteristics. A normal spark plug will have an insulator skirt and electrodes appearing grayish-white, grayish-yellow, or light brown. A properly functioning spark plug typically 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 is contaminated with oil or deposits but is otherwise undamaged, it can continue to be used after cleaning off the oil and deposits. If the spark plug is severely damaged, showing blistering, black streaks, cracking, or melted electrodes at the tip, the cause of the damage should be identified. After troubleshooting, replace the spark plug with a new one. Additionally, if the spark plug appears blackened as if smoked, it indicates the wrong heat range was selected or the air-fuel mixture is too rich, possibly with oil leakage.