What Causes the Motor to Spin Idly?

[OGiselle]

Motor spinning idly can be attributed to the following reasons: 1. Severe wear of the starter carbon brushes: The symptom during startup is weak starting power, and the crankshaft can be clearly seen turning very slowly through the belt and pulley. When the wear is extremely severe, the starter cannot drive the crankshaft to rotate at all, only producing an electric current sound. 2. Damage to the starter clutch: Normally, the starter operates at a speed of 120r/min, while the engine idles at around 900r/min after starting. The function of the clutch is to prevent the engine from driving the starter in reverse after startup, which could happen if the driver fails to release the key in time, causing the small flywheel gear and large flywheel gear to remain engaged, leading to the starter burning out.