For a four-stroke motorcycle engine, the valve is an indispensable part. The quality of this part will directly affect the performance of the engine. As for the symptoms and adverse reactions after it breaks, the following will be analyzed one by one.

First of all, let's take a look at the motorcycle engine valve is what? From the literal meaning of this part is similar to a door, but the door in and out, is a kind of special gas.

This type of gas is also called a combustible mixture. It is a mixture of fuel and air. With the presence of this gas, the engine can ignite normally.

As we all know, if a motorcycle engine wants to work normally, it must have a process of inhalation, compression, workmanship, and exhaust. During this process, the valve will open and close at the right time to ensure that the engine inhales fresh combustible mixture Gas, and remove exhaust gas in time, so that the combustion of the engine is always in the best condition, allowing it to maximize its power performance.

In this process, if the valve is not opened and closed in time, it will affect the combustion effect of the engine, which will cause the vehicle's power to drop, fuel consumption to increase, and even fail to start.

However, according to the characteristics of motorcycle engines, it is unlikely that the opening and closing of the valve will be delayed. On the contrary, air leakage will occur due to its own wear and carbon deposits, as well as changes in valve clearance.

Once the valve leaks, the cylinder pressure of the engine will drop. Therefore, the most direct response of the motorcycle at this time is the power drop, weak acceleration, difficulty in starting, and even frequent flameout under high temperature conditions and unstable idling.

As a very inconspicuous small part, the oil seal's main function is to block the lubricating oil from leaking, and the valve oil seal, as a built-in oil blocking part, mainly acts to block the lubricating oil from entering the combustion chamber.

Here may be a lot of small partners will be a little strange, the engine lubricating oil is not the lubrication of the whole machine? Why block the lubricating oil into the combustion chamber, if the piston and cylinder block how to lubricate it?

It is normal to have this kind of question, but we must know that once the lubricating oil enters the combustion chamber, the current engine will burn oil, so the existence of the valve oil seal is very necessary. The lubrication of the cylinder block by the lubricating oil is not carried out through the combustion chamber, but by splashing the lubricating oil on the cylinder wall. In this way, the contact surface of the piston ring, piston and cylinder block will always be in The best lubrication state, and because of the existence of the piston ring, excess lubricating oil will not enter the combustion chamber.

Therefore, once the valve oil seal is damaged, the engine will burn oil.

According to actual maintenance experience, the oil burning of many engines is not caused by the cylinder block being pulled and the piston ring aging. It is precisely because the valve oil seal is aging, inelastic, and unable to block the lubricating oil. Therefore, when our vehicle When there is an oil burning failure, the valve oil seal must be checked. Otherwise, the newly replaced piston ring may not be able to eliminate the oil burning failure.

Through the above introduction, we can see that after the motorcycle valve and valve oil seal are damaged, the most common failures of the engine are power drop, weak acceleration, difficulty in starting, and oil burning. The most direct way to judge whether the current vehicle has this phenomenon is to suppress the cylinder block and observe the exhaust pipe exhaust. If the cylinder pressure of the current vehicle is significantly lower than the design standard, and the exhaust pipe still emits blue smoke, Then the current engine may have excessive valve wear, too small clearance, and aging oil seal. At this time, it must be eliminated gradually. If you continue to ride, it will only make this performance worse and worse.