Usually the spark plug life 15000km, long-acting spark plug life 30000km. When the engine works, the spark plug insulator skirt temperature should be maintained at 500~ 600 ¡æ. If the temperature is too low, the insulator is easy to deposit, may cause leakage resulting misfire phenomenon; if the temperature is too high, easy cause preignition and detonation.
Spark plug in use of common breakdown phenomenon are as follows:
( a ), severe erosion of spark plug. Spark plug top up scar, destruction or ablation electrode melting, that spark plugs have been destroyed, should be replaced. The replacement shall be checked during ablation of the signs, as well as changes in color, in order to analyze the cause of fault.
(1) electrode and an insulator is melted white. Indicates the combustion room temperature too high. This may be a combustion chamber deposit is excessive, so that the valve is too small space caused by exhaust overheating or cooling device working poor, may also be the spark plug without the required torque tightening etc..
(2) electrode and an insulator having round scar. Show engine pre-ignition, may be premature ignition time or low octane number of gasoline, spark plug too advanced reason.
(3) the top of the insulator. Detonation combustion is the main reason of insulator rupture. While premature ignition time, gasoline octane number is low, the combustion chamber temperature is too high, it may lead to engine knock combustion.
(4) the top of the insulator with black stripes. The stripe sign spark plug has leakage, should change new.
( two), a spark plug having sediment. Spark plug insulator tip and electrode sometimes sticky with sediment, serious when can cause the engine not working, such as cleaning the spark plug can temporarily remedied. In order to maintain good performance, must identify the root cause of failure.
(1) oily sediment. Spark plug having oily sediment, indicating the lubricating oil enters the combustion chamber. If only individual spark plug, valve stem seals may be damaged. If the cylinder spark plug is stuck with the sediments, indicating cylinder oil, should check the air filter and ventilation device is blocked.
(2) black sediments. Spark plug electrode and the internal black sediments, indicating a rich mixture, can increase the running speed of the engine, and continued for a few minutes, you can burn in the upper electrode layer of black soot layer.
