RE: Re-using Zagi motor
That motor is a Speed 400 size motor. Or most of the older Zagi are that. Be sure to keep oil on the bearings.
It cost about $10 max and you throw away after the brushs are worn out.
Once you are up and flying it is worth it to replace with a better motor with bearings. It will be more effiecient so your flight times will be extended and less heat in all of your electronics.
The better replacment will run you $20-$25 but will last much longer.
Good Luck and have fun.