Yu Qiran Products

How to avoid the chainsaw engine scoring cylinder ? The reasons and prevention

Chain saw is one of the most widely used and most frequently used power tools among many garden machine products. Because it has very sharp teeth and is used for high-speed cutting of wood, strict safety precautions must be taken when using it. So, what to do when there is a problem with the chain saw engine? What is the reason why the chain saw engine scores the cylinder? The following editor will give you a specific introduction, hoping to help you.

How to judge that the chain saw engine is scoring the cylinder?

The phenomenon of chain saw engine scoring cylinder. The scoring cylinder in the chain saw cylinder is seized. Just check the piston of the chain saw. Under normal circumstances, there are several reasons:

  1. Serious carbon deposits on the top of the piston of the chain saw and around the ring

Mainly caused by the use of bad engine oil, such as the use of diesel engine oil or inferior two-stroke engine oil.

  1. scoring cylinder on the exhaust side of the chain saw piston

The air filter of the chain saw is dirty, garbage is clogging the carburetor fuel, the adjustment is too small or the oil is added in the fuel too little, so that the concentration of gas entering the cylinder is reduced, and the lubrication is insufficient due to the leakage of the paper pad insulator, causing high temperature Easy to score the cylinder.

  1. scoringthe cylinder on the lower side of the air inlet of the piston of the chain saw

Basically, water has entered, such as use in rain or snow. Water enters the cylinder from the air filter of the chain saw, so that the lubricating oil film is mixed by the water, and the lower side of the suction side of the piston of the chain saw lacks the lubricating oil film. After high-speed operation, heating causes cylinder scoring;

  1. The air intake side of the piston of the chain saw scores the cylinder because of the garbage entering from the air filter;

Causes and troubleshooting of chain saw engine cylinder scoring

There are many reasons for the cylinder scoring of the chain saw engine. First of all, what is the cylinder scoring? First of all, we should talk about the chain saw engine. When the engine is working, the piston and piston ring make high-speed reciprocating motion in the cylinder. Due to the huge expansion thrust generated by the combustion of the mixed gas, the piston and piston ring are in close contact with the inner wall of the cylinder through the oil film formed by the oil. Under normal circumstances, due to the isolation and cushioning effect of the oil film, the piston and piston ring do not directly contact the cylinder. However, under certain circumstances, the two will directly contact, causing sliding friction and generating a lot of heat. If the heat dissipation conditions are not effectively improved, it may melt the metal surface of the piston, piston ring or the inner wall of the cylinder, and cause the sliding friction surfaces to fuse together, causing longitudinal score marks during the high-speed movement of the piston. Cylinder phenomenon. So, what are the reasons that cause the chain saw to score the cylinder?

  1. The initial run-in of the chain saw engine is insufficient, and the cylinder is scored due to high-speed operation

For a chain saw that has just been shipped from the factory, you can see with the naked eye that the inner surface of the cylinder of the chain saw engine and the pistons and piston rings are very smooth. If you use a magnifying glass, it is actually composed of many uneven protrusions. During the engine running-in period, you must correct The surface is run-in, and the protrusions are cut off, so that the surface is smooth and the force is even, so that it does not bite when sliding, and the operation can be smooth. Therefore, the new engine must undergo a certain degree of running-in after assembly. Otherwise, the higher protrusions on the mating surfaces of the piston, piston ring and cylinder will bear a concentrated load, and the pressure per unit area will be very large. After friction, the temperature will rise, and the protrusions will soften and melt, causing the cylinder to be scored.

Second, the overheating of the piston of the chain saw can also cause the cylinder to be scored

Local abnormal expansion occurs when the piston is overheated. Due to the deformation of the piston, the piston ring groove is twisted into a wave shape, and the piston ring and the piston ring groove bite together briefly or even for a long time, causing the piston ring to fail to work normally. At this time, the edge of the piston ring directly touches and rubs against the inner wall of the cylinder with extremely high pressure per unit area, so that the piston ring not only loses the function of sealing the combustion gas, but also destroys the oil film on the inner wall of the cylinder, causing cylinder scoring. The main reasons for the overheating of the piston are: poor gasoline quality, resulting in abnormal combustion of the mixed gas and high temperature; poor fuel supply system, ignition setting or adjustment, resulting in abnormal combustion of the mixed gas and high temperature; poor design of the piston body or piston aluminum parts The poor density causes the piston to overheat due to insufficient heat transfer from the piston to the cylinder.

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