The function of the exhaust pipe universal drum is to discharge exhaust gas and change the characteristics of the engine according to different universal drums. During the exhaust system, due to the inertia force, a low-pressure belt of the vacuum pump will appear after the exhaust gas, rotating towards the engine outlet, and the low-pressure belt of the vacuum pump will rotate with the valve. If the duration control is close to the end of the exhaust process when the intake valve has already opened and started to intake, that is, when both the exhaust valve and the intake valve are opened at the same time, the low-pressure belt of the vacuum pump will open both the exhaust port and the intake port due to the suction force of the vacuum pump. The low-pressure belt of the vacuum pump will be discharged due to the suction force of the vacuum pump, and fresh mixture will be sucked into the cylinder, thereby improving the intake efficiency of the engine. If a 1000ml motorcycle has an actual intake efficiency of 70% at 10000r/min, it is also good. Due to the fact that the engine exhaust valve cannot completely exhaust exhaust gas in a very short period of time during high-speed driving, the intake valve cannot fully intake air. The inertial force generated by this type of exhaust is of great significance for improving engine characteristics.
