You need to increase your idle speed:
1. Take the plastic floor covers off.
2. You will see the carburetor on top, towards the rear of the compartment you just opened. Consult the attachment for an idea of what it looks like (note that the carb in the diagram is rotated on its side).
3. Warm up the engine --go for a 10 minute ride.
4. Tighten the <i>stop screw</i> (see diagram) a few turns. The stop screw will be accessible from the right side of your moped.
5. With the engine running on the stand, slowly loosen the <i>stop screw</i> until the rear wheel no longer spins (stop the wheel from time to time with the rear brake to check). You want the engine running fast enough that it won't die, but slow enough that the rear wheel won't turn at idle.
If you cannot get the rear wheel to stop turning without the engine dying let us know.