As a general rule, if the motor was too hot to touch, then either the motor is defective/damaged, or the motor is of the wrong kV, or the prop is too large.

When you get your new motor, check the power system on a wattmeter to be sure you are not drawing more current than specified for the motor and ESC. Excessive current could damage the motor, the ESC, or both. If you are using the recommended Power 25 870 kV motor, its maximum continuous current rating is 32A with brief bursts up to 44A. As guver suggests, you may have been drawing quite a bit more than that, for whatever reason. A wattmeter is a must!

- Jeff