Sang because no motor "Color" markings on the motor "or" ESC?
This is not a snag and it would be a great exercise to have the motor / ESC / Receiver / Battery all activated before you assemble the model to make sure all Electronics work before committing to taking all out from the box, just in case something with Electronic System does not work. This is what I do for all my new models and I go ahead and test motor / ESC / battery / Receiver / Transmitter all in one system to make sure it works. Should there be something wrong with a servo, I just replace but, at least the major command and control has been checked out.
Additionally, the rotation of the motor is checked while testing as described above and if the motor is spinning the wrong way then, all you do is switch two wires between Motor / ESC.
If you check my attached picture of my motor if has COLOR CODED orientation (Yellow, RED, BLACK)!
