Yes it would but I'm talking about a rear rack setup. If you were looking at the bike from the front , you would see a seat, the "drive wheel" and then the engine.
The set up I built was with an electric motor so I was able to turn the motor upside down, solving the bike wanting to go in reverse, if you know what I mean. It would be interesting to see a china girl run upside down, I think the carb would have to be mounted in reverse and everything would be fine. As far as welding your wheel, have a look at the cheap electric scooters. All the parts you need are there, including a small drive wheel with a sprocket attached. It's very hard to put into words but I will help if you ask.