Once back, I proceeded to look for information on the bike. It turns out that this early Chinese (or Japanese, or Korean, or Taiwanese, or wherever it actually came from) import "moped" was only available through mail-order starting in 1987 and was advertised as a "free motorcycle" if you paid the $400 shipping bill. Moped Army has a pretty interesting write-up on this mystery moped on their Wiki. Between the dual gas tanks (one on the down tube and another under the seat), the BMX wheels underneath it, and the knock-off 47cc Sachs 505-1A 2-stroke motor, it is truly surprising that this thing will actually go 30+ mph depending on what you ate that day.
Okay, so it's a piece of junk. Why am I bothering to write this other than to complain? Because I've got a few ideas on how to improve it and possibly make a "real" moped out of it. Sure, it's akin to polishing a turd, but why not?
The plan is to ditch the little 47cc motor completely unless, through some miracle, I'm able to find a cheap Sachs 505-1A motor for sale on eBay or at least a Sachs pedal crank assembly to replace the broken one. Since I doubt that will happen, the next option is to just replace it.
Instead of the little 2-stroke, I'm leaning toward picking up a 4-stroke 110cc Lifan or Loncin engine and jimmying it into the frame where the Kamasura motor currently sits. This will of course require modifying the motor mounts somewhat and doing something with the front tire to keep it away from the motor. But why stop there? If I'm going to be welding on the frame, I may as rake the front forks out a few degrees to push the front tire out farther to clear the motor and also allow me to replace the BMX wheels with standard 16" moped rims and tires (with wide whitewalls). After that is done, I'd ditch most of the brittle plastic parts off the bike and rewire it to run a new 12 volt headlight, taillight, and turn signals. Then do a bit more customization that includes new stitched leather grips, new leather seat, a satin black paintjob, red rims, a new front fender, and some gratuitous pinstriping to make it look something like the image below.
Or I could just ditch the whole thing and chalk it up as a loss. Either way, it's an idea...