When you strip the threads out of your motor mount just get a slightly longer screw, and a nut to secure it
Photo shared from Facebook group.

When I swapped the RS2205s off one quad to another there was a bit of galvanic corrosion between the carbon steel screws and the Al housings and the housing threads were toast. I used A304 M3 x 3mm helicoils (50 cents each) and re-tapped them with a Dremel and a 3.15mm bit (needs the work stand). The above is even easier, but doesn't work on closed housings