Taking copper wire out of the electric motors can be worth it if the electric motor is easy to break down and the copper is easy to remove from the electric motor.
I've broken some electric motors down and removed the scrap copper easy and those were worth it. But I once found an electric motor that although it was easy to get the electric motor apart the copper wasn't so easy to get out and it ended up taking me over an hour to get half the copper out before I gave up.
At that rate I maybe made $1.00 an hour.
If the wire is easy to remove then I say it's worth it to remove the scrap copper but if the wire is hard to remove then just sell the electric motor as is for scrap.
I sometimes can get up to $12.00 for a scrap electric motor if they're big and it's usually better to sell as is and move on.