Our initial design for this project was very simple. Two small, fixed-gear bicycles welded parallel with a frame in the middle (to look like a carriage/cart type thing). Then, we'd mount an old horizontal-shaft lawn mower engine on it. We'd connect the output of the motor via slip clutch and V-belts to the bike's drive sprocket and tie the steering together. Then, we'll install more brakes if needed.
That was the idea, but didn't exactly work out like that.
(And sorry there are no pictures of the build. I decided to do this instructable after I had already finished it, so the documentation is mostly text. Hence why the metal is so rusty in all of the pictures...)
Step 1: Get a Motor
The next step in getting the motor ready was to clean the carburetor. The idle was really rough and it was evident that the fuel mixture wasn't being delivered properly. I pulled off the carb and cleaned the entire thing with Gumout carb cleaner. Those chemicals are nasty and will eat through anything, including latex gloves. I soaked the carb in the Gumout and using a toothbrush to knock off old deposits. I replaced the gaskets to the fuel tank and the head, and the motor ran much better. I could use the fuel adjustment screw to adjust the amount of fuel getting to the motor, and tuned it to a nice low idle speed.
Now, the motor was ready to be put into action.