G'day Iain, I don't know about the derestrictions, but, it sounds like you have a wire off or a bad connection on either your ignition switch or cdi. I am not sure about sym, but kymco used a black/white wire on the cdi. When the switch was turned to off it would earth this wire stopping the engine. This may not be your problem, but a place to start looking.
oops, only just saw the date of the post.
