The structure of the chain saw spark plug is the same as the commonly used automobile spark plug. The whole is divided into two major components according to the material of the insulator and the metal shell; according to the structure, it is divided into three parts, namely the central electrode, the steel body and the electrode, and the insulating ceramic core. The upper part of the steel body is made of hexagon for easy disassembly and assembly of the wrench, and the lower part has threads which can be screwed into the cylinder head. The metal shell has threads for screwing into the cylinder; the shell is equipped with an insulator, which penetrates a center electrode, and there is a terminal nut on the upper end of the center electrode to connect the high-voltage wire from the distribution board; There is a ground electrode welded on the lower end surface, and there is a gap of 0.6-1.0 mm between the center electrode and the ground electrode. The high-voltage electricity will burst into the ground through this gap and ignite the mixed gas.

Chain saw spark plug function
The spark plug of the chain saw is generally installed on the top of the middle cylinder, conducts the current generated from the high pressure package, and guides the combustion of the mixed vapor in the cylinder, which plays an important role in the operation of the engine; it depends on the gas (air) under the influence of certain factors. The gas discharge principle, which can dissociate and become a conductor, uses the high pulse voltage generated by the ignition system of the gasoline engine to break down the gap formed between the center electrode and the side electrode of the spark plug. When the gap is broken down, due to ions and electrons The high-speed movement of the gas forms a high-temperature and hot ionization channel, and an arc spark is generated, which ignites the compressed combustible mixed gas in the combustion chamber of the gasoline engine, and the mixed gas burns and expands to complete the work stroke. The spark plug is the terminal of the circuit, and it bears a large amount of work. It is one of the main functions of the chain saw accessories that cannot be underestimated.

Disassembly, assembly and maintenance of spark plugs of chainsaw
There is a hexagonal nut at the rib of the spark plug of the chain saw and the insulating ceramics, which can be disassembled and assembled with a 19MM elbow sleeve. Most chain saws are equipped with a T-shaped three-purpose wrench; because the chain saw uses mixed gasoline, the spark plug will be more Other spark plugs powered by pure gasoline are more likely to accumulate carbon. The spark plug of the chain saw should be maintained frequently to ensure that the chain saw works normally; if the spark plug of the chain saw has carbon accumulation, the spark plug should be immersed in gasoline and cleaned with a brush, or use sandpaper Or use a harder metal object to scrape the carbon deposits on the electrode. Do not grill directly with fire. Although this looks like it can remove the carbon deposits, long-term direct grilling will cause problems with other parts of the spark plug of the chain saw and reduce the service life of the spark plug. 

It's easy to remove the spark plug. Just use a "spark plug socket" wrench. One thing is very important during installation. Don't screw the spark plug too tightly. Too tight can damage the threads on the cylinder head, especially the aluminum cylinder head. When installing, hold the spark plug sleeve first, tighten the spark plug, and then tighten a 1/4 turn with a socket wrench. If the spark plug is not fitted with a washer but has a tapered mounting seat type, because the steel body of the spark plug directly touches the cylinder body, it can only be screwed in 1/16 turn with a wrench after the hand is tightened, so as not to cause damage to the cylinder body. hurt.