Why does Suzuki UY start the throttle a little loud after running 20 thousand kilometers?

Click is the sound of the air valve, and the sound behind it may be caused by the vibration of the license plate.

Different brands of engine oil have different kinematic viscosities at high temperature, even the same brand of engine oil. The engine with high viscosity has low sound, while the engine with low viscosity has high sound. Whistle will also change with the viscosity of this oil, including high viscosity low whistle and high viscosity high whistle.

In this case, you need to change the oil every 1000 km. If the noise is too loud, the spark plug needs to be checked, and the carburetor needs to be removed and cleaned.