i just watched your video i would definitely say to change the one way bearing. sounds like mine did when it would spin out. it takes about 5 minutes to change the bearing and i would recommend to your client to go back to the pull start. mine has not given me a problem when it comes to starting since i changed except for the usual issues such as clutch shoes and springs and also losing the screw on my clutch bell due to my own stupidity of not putting loctite on the screw.