in my experience with new machines that heat up, even old ones. sometimes theres a issue with the binders slightly connecting/touching the frame body. sometimes it so slight you cant really see it, causes a short making the motor heat up.
if your able to pull the motor from the frame hook it directly up to the PSU and turn on for a few minutes, see if it still heats up. if it does the motor is bad, if it dont then its a connection problem mostly likely in binders where the motor wires connect to the rca or binders directly.

hope this helps.