How to adjust the noise of Wuyang Honda 125-F new valve?

Motorcycle valve clearance can be adjusted in cold state, but not in hot state. Due to the design characteristics of the ejector pin engine, the valve clearance will change when the engine is hot or cold, that is, the metal will expand when the engine is hot, but the materials of cylinder head, cylinder block and other parts are different from the valve ejector pin, and the expansion coefficient will be different after heating, that is, the expansion of aluminum cylinder head and cylinder block will be greater than that of steel valve ejector pin, which will lead to the phenomenon that the valve clearance will automatically increase after the engine is hot and return to normal after the engine is cold. If your car is like this, then you don't need to adjust it. It is normal. Under normal circumstances, it is necessary to use a feeler gauge to adjust the valve, but under normal circumstances, it is entirely by experience, and few people will use a feeler gauge to adjust the valve. The smaller the valve clearance, the better. If it is too small, it will cause failures such as lax closing and abnormal wear. The minimum valve clearance can be adjusted to 0.05, but it is best to follow the instructions. It's normal to make a little noise, which is better than causing a fault. Moreover, after warming up, the viscosity of the engine oil will also decrease, the formed oil film will become thinner, the lubrication effect will become worse, and the sound will increase accordingly.