The power of an ideal motor that experiences no torque is zero. The reason this is theoretically possible in an idea motor is that a motor spins when a voltage is applied to it and a motor generates a voltage when it spins. If you have no power losses, the voltage generated by the motor as it spins exactly cancels the voltage that is spinning the motor, and you have no current passing through the coils. Since it is never possible to have a lossless system (there will always be friction and the coils will always have some resistance), you won't ever see this in a real-world motor.
- Ben