What about this scenario. You have a legally registered motorbike, but keep it for recreational use on weekends only and/or have it safely locked up when you're not riding it. Since it's legal, it's expensive, and you go to great lengths to take care of the bike and deter locals from stealing it. Meanwhile, you also have an illegal scooter for zipping around the city and commuting to work. The scooter is not so expensive. You still take care of it and ride safely, but if a local stole the bike or the police confiscated it, then it wouldn't be the end of the world as you could always get another one.

As for gasoline, you fill up the legal bike with your legal plates, and then siphon some of the gas into the scooter.

For the most part, the bike is used for long-distance rides in and out of the city, and the scooter is used for commuting in the city.