What are the causes of weak starter operation?

[MacLucy]

The causes of weak starter operation are: 1. Insufficient battery charge or loose, poor-contact connecting wires; 2. Starter bearings being too tight or excessively loose; 3. Burnt starter switch contacts or short-circuited electromagnetic switch coils; 4. Open or short circuits in the series auxiliary coil of a moving-armature starter. The symptoms of weak starter operation include: 1. The starter rotates slowly and weakly, making it difficult to turn the engine; 2. Upon engaging the starter switch, the starter only produces a clicking sound without starting. The starter, also known as a motor, converts the battery's electrical energy into mechanical energy to drive the engine flywheel rotation, thereby enabling engine startup.