How does a good motor of a Phantom 1.1.1 feel when you turn it by hand? Two of my motors are completely smooth (no real friction). But the other two always move with the same interval (like a gear). It feels like the inner magnets are much stronger and 'click' into place. I'm asking, because one of the two motors with friction is also making a little bit of vibration. When I remove all the props and start the motors, one of the four arms is vibrating more then the other three.