DJI introduced these CCW motors in their second generation Phantoms (version 1.2). CCW motors have left-hand threads and can easily be spotted by their black propeller nuts. If you replace the correct motors then eventually the turning direction of the propellers (and their fixing nuts) and the thread direction are always opposite to each other for all four motors. This greatly helps with avoiding propeller nuts getting loose in operation.
If you don't replace the correct motors then you are actually making things worse. Then, all four motors will have their thread directions matching those of their propellers. You then will loose any safety advantage.
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| Top: DJI's video showing a second generation Phantom. Bottom: my upgraded DJI Phantom; the black nuts are in their correct positions. |
This still from DJI's tutorial video is proof: my soldering iron can be kept cold, as my musings are correct. Lucky, me...
