Acceleration system
When the internal combustion engine accelerates, the throttle valve opens suddenly. The mass of fuel is larger than that of air, so the inertia is also large, and it is difficult to increase the fuel supply in time, so the mixture becomes thinner instantaneously, which makes the engine speed increase slowly, and even the intake pipe flashes back or stops. Therefore, there is often an accelerator pump, which is driven by the throttle valve through a pull rod and a spring. When accelerating, the accelerator pump injects fuel into the throat; when the throttle valve is slowly opened, the fuel returns to the float chamber through the fuel inlet valve of the accelerator pump, and the fuel injection is stopped.