Hi Justin:
Have you put a fresh spark plug in your moped? That's the first thing to try.
If you've changed your plug and the problem hasn't gone away you probably need to adjust your timing. Clean and adjust your points as described in <a href="http://www.mopedarmy.com/forums/discuss/read.php?f=1&i=9931&t=9931">Fred's guide</a>.
Chris.