In 25 years of racing I never seen broken shaft on a motor like that and to have more than one do it is really strange. Something is just no right thats for sure. I been racing my CC motors for 7 months and no problems. I race at a very brutal indoor track during the winter where track temps are around 35 degrees on rock hard clay with slicks. Traction is unreal and still no breakage of motor shafts.

Not sure what it is but it is really out of the ordinary to break shafts like that.