Circular saw motor is smoking or smells hot

Symptoms

• Visible smoke from vents near the motor
• Strong hot or burning electrical smell
• Motor bogs down or slows under normal load
• Sparking visible through the vents

Likely causes

• CommonWorn carbon brushes arcing against the commutatorWorn brushes spark and generate heat and a burning smell.
• CommonMotor clogged with sawdust, trapping heatBlocked vents prevent the motor from cooling properly.
• CommonRepeatedly forcing a dull blade through woodOverloading the motor for extended periods overheats it.
• PossibleBearing failure causing excess frictionA failing bearing adds drag and heat to the motor.
• Less commonInternal winding damageLong-term overheating or an old motor can damage the windings themselves.

What to do

1. Stop the saw immediately and unplug it or remove the battery; let it cool fully before touching it.
2. Blow out sawdust from the motor vents with compressed air once cooled.
3. Check the blade for dullness, since a dull blade forces the motor to work much harder.
4. If accessible, inspect carbon brushes for wear and replace them if they're short or the springs are weak.
5. Avoid prolonged heavy cuts in dense material without letting the saw rest periodically.
6. If smoking recurs after cleaning and a brush check, stop using the saw and have the motor professionally inspected.

Tools and parts

• Compressed air
• Screwdriver
• Replacement blade if needed

When to call a pro

If the motor smokes again after cleaning and a brush replacement, take it to a tool repair shop rather than continuing to use it.

Safety