Normal operations The nose of insulator appears yellow-brown, brown or lightish gery, electrode erosion is light. It shows the spark plug is suitable for the engine.

• 正常状况火花塞绝缘体裙端呈黄褐色,褐色或浅灰白色,电极烧蚀很小,表明该火花塞与发动机是匹配的。