Why is the scooter engine making a ticking sound?

[LaEmmett]

The causes of abnormal noise in the scooter engine are as follows: Engine intake pipe leakage: The intake system has many intake manifolds or various valves. Leakage in these components can allow unwanted gases to enter, causing the concentration of the air-fuel mixture in the intake manifold to become too high or too low, ultimately leading to intermittent engine shaking or weak idle symptoms. Fuel system blockage or malfunction: Due to a blocked fuel tank vent hole, clogged fuel tank switch, fuel filter, or the fuel line between the tank and the carburetor, the engine cannot receive the corresponding amount of fuel during idle, causing the air-fuel mixture to become lean, resulting in weaker engine power output and idle shaking.