Why did the motor start smoking and then quit?
Your pressure washer may be overheating if you are using an extension cord that is longer than 50 feet or lighter than 12 to 14 gauge. It can also overheat if your pressure washer is turned on without any water running through it or with the gun trigger released. Lastly, there may be a problem with the motor.
A smoking motor is a serious condition. If your unit is under warranty, take it into the nearest Campbell Hausfeld service center. If it is not under warranty, you should take it into the nearest service center or call Campbell Hausfeld Technical Support at (800) 543-6400.