Originally Posted by
motoclay
+1 collet sounds like the issue....however, if you are starting it with a bump box that still seems unlikely. Make sure all of the drive pines are good. Even on the wheel output shafts...be through, it will be obvious ....
Starting on the bump you'd be placing pressure on the flywheel...which will let the flywheel grab on the output shaft via the collet even if the collet is not a tight fit on the flywheel/shaft, due to the pressure placed pressing down on the car. Quite possible situation.