The two stroke Chinese bicycle motors are a bit iffy, some people have had ok luck, others have had them break down with only a few miles. A honda 4 stroke would probably be more reliable but they're more expensive, especially if it had a cvt drive to a sprocket or pulley on the wheel. There are friction roller drive models that are cheaper and easier to install, but roller drive sucks in the rain and wears the tire out faster. Sometimes you can find those little honda motors for a good deal on those miniature garden tillers.