Just playing the devils advocate here but there are thousands of Liondrive engine out there and having the drive come loose from the shaft is pretty rare. More common are drive nubs wearing off requiring replacement of the whole motor. I had to replace the motors in a Legacy Baldwin Shark engine that was only a year and half old. It was run often by a local club but no more than dozens of other engines that had ten times as many miles.
This was all about cutting costs replacing steel and bronze machined gears with two pieces of diecast metal.
Pete
