DIAGNOSIS The motor is overheating due to a short or excessive friction. This is often a failing armature (the spinning part of the motor) or worn motor bearings creating drag.
FIX Stop using it immediately. Replace the motor assembly.
- Remove battery and housing screws.
- Separate the motor/trigger unit from the transmission.
- Disconnect the motor wires (note their positions).
- Swap in the new motor, reconnect wires, and reassemble.
IF THAT DIDN'T WORK If a new motor also overheats, the fault is in the trigger/switch assembly. It might be sending erratic voltage, causing the motor to over-amp. Replace the trigger switch module.
HEADS UP The burning smell is insulation melting on the motor windings. This is a critical failure. Continuing to use it is a fire risk and will completely destroy the motor, making it un-repairable.