I suspect it's the RCfoamfighters video being referred to here.
http://www.youtube.com/watch?v=D4UKWvTHX1IMost outrunners have the prop mounted on the rotating magnet case side, but a few are reversed so that the prop shaft comes out through the motor mount side for mounting inside the nose of an aircraft..... It is difficult to use this latter type motor for a pusher motor, so the shaft needs to be moved to the other position with the extended bit poking out from the rotating case. I've done a couple, but I've ordered replacement shafts from another source to avoid having to use the locking collar.
Why did I modify these motors? Simply, the specs on the motor I used are pretty rare, but perfect for my purpose and the only other motor that I know of that has the shaft the right way, was over double the price of the Turnigy motor I used. Shafts from RCtimer were only a buck or so each with shipping so the math said use the Turnigy motor w/RCtimer shaft.
Regards
Christian