DIAGNOSIS Friction is creating excessive heat. This is almost always due to a dull blade, too high an orbital setting for the material, or forcing the cut too fast.
FIX Stop immediately. Let the tool cool. Change to a new, sharp blade. For metal or dense composites, ensure you're using the correct blade (fine tooth for metal) and set the orbital dial to 0 or 1. Apply steady but gentle forward pressure and let the blade's teeth cut—don't muscle it.
IF THAT DIDN'T WORK Inspect the plunger mechanism for binding. Sawdust packed into the plunger guide can cause friction. Clean it out with compressed air and ensure it moves freely by hand.
HEADS UP The burning smell could be the workpiece, not the tool. Cutting laminates or plastics with a wood blade will melt the material. Match the blade to the material. A continuous burning smell from the motor housing indicates a more serious issue—stop use.