Diagnosis
The thermal overload protector on the motor is tripping. The motor is overheating.
How to Fix It
The motor needs better cooling. Make sure the air vents on the motor housing are not blocked by leaves, dirt, or placement against a wall. Clean them with compressed air. Operate the machine in a well-ventilated area, not an enclosed shed.
If That Didn't Work
The motor's start capacitor might be weak, causing the motor to draw excess amps and overheat. A multimeter can test capacitor microfarads. Replace if out of spec.
Heads Up
Repeated overheating damages motor windings. If it keeps happening, the motor will eventually fail completely. Address the cooling issue now.