This is my roommates KTM Foxi GT. We did a little bit of work to get it to be a reliable daily rider:
The fuel lines were all replaced. The carburetor was cleaned out, the electrical system was kind of iffy, some of the switches were damaged so the headlight was hardwired in the controls, the original tires were still on it, they were replaced with IRC universal tires, stock size, the chain was cleaned and lubed with motorcycle chain spray, brakes cleaned and adjusted, joints greased, then the bottom end fluid changed out with ATF Type F. It has a Sachs 504 motor on it. I have heard rumors that you can easily fit an Puch E50 on it. Like the the frame was designed for it, the Sachs 504 motor was put on as an afterthought with custom brackets. There are plans to shoehorn in one here sometime. It is purchased, just needs to be rebuilt and put on.
It is a pretty solid rider.