Reason 1: deviation of fixed magnetic steel
Treatment: rebonding
The gap between 2: carbon brushes is not uniform
Treatment method: correction of carbon brush gap
Reason 3: there is a short circuit between the positive and negative electrodes of the battery
Treatment: elimination of short circuit
Cause 4: turn to turn short circuit
Treatment: fat tire electric bike
Cause 5: commutator short circuit
Treatment method: clean up commutator blades
Reason 6: too tight fit between shaft and bearing
Processing method: grinding shaft
Reason 7: zero start of Electric vehicle
Treatment: avoid driving as much as possible
Reason 8: heavy load or heavy driving resistance
Approach: human assistance