What are the causes of a weak starter operation?

[OCameron]

The causes of a weak starter operation include the following points: 1. Insufficient battery charge or oxidized wire terminals: When turning the starter switch to the start position, if the engine rotates when decompressed but the starter does not rotate or struggles when not decompressed, it is likely due to insufficient battery charge or oxidized wire terminals. 2. Poor contact between the brushes and the commutator, or partial short-circuit in the motor winding: If the starter rotates very slowly when decompressed and sparks occur at the commutator, it is mostly due to worn brushes or commutator causing poor contact, or short-circuiting of the commutator copper segments. 3. Armature rubbing against the magnetic poles or damaged coil insulation: If the starter rotates very slowly when decompressed and produces noise or smoke, it is mainly caused by the armature rubbing against the magnetic poles or damaged coil insulation.