I bought this off eBay from Gene Bollmeier and it had a bad clutch disc. It was actually stuck! I replaced the clutch disc and drove it around through the summer.
These are nice running motorbike's also called the "Stink Motor" in England. They are 2 cycle engines do they smoke a little.
The smoke would be behind you since that is where the engine is at so I would think the wind would have to be blowing the right way to get smoked out.
They made 2 different models the 25cc and the 34 cc model
Here is the bike after it was working. The thing was a kick to drive around town. You could pull up next to people and they would not even know you were motorized. The engine ran smooth and quite.
Here is the Cycle Master after I sold it on FeeBay. Brian Kunzog owns it now and he put it on a 1950 Indian bicycle.
Here is Brian Kunzog's Web Site