When I got my Johnny M, I ordered new parts, balls, rubbers, post etc. Made the effort to research the type of ball to use because of the magnet on the pin, got all the gear put in then after a couple of days the balls were getting stuck in the ball trough, they wouldn't roll down to the popper. After taking ball trough apart expecting to find divots I discovered all the balls had been magnetised, I then checked my order I made thinking I'd been sent the wrong balls.
No I WAS an idiot and ordered the wrong ones, always worth double checking before you press the buy button!!!!