[jhautz]

The flat spot is probably in the perfect place to the prop adapters tha airplane guys use on the motor shafts. Remeber... these were originally designed as airplane motors and we just use them in our ground application. Nue primary market is still air.

That being said... I agree. Dumb to place it in only one spot. The whole length should have just a small flat. 1mm wide flat would do it.