How damn funny. I revisited this and completely forgot that I'd started a thread four years ago on it.
http://www.mopedarmy.com/forums/read.php?7,1962685,page=1
The reason why I went searching again is that I got to thinking about the video that is linked in the wiki. Seems to be a lot of agreement on the idea of setting the stator at some arbitrary point (usually full advance) and fiddling with the timing via the points gap.
Think this through a sec. Yes the points gap affects timing.. per se. But that is secondary a (and unintentional) result of setting that gap. The gap is primarily intended to set your "dwell"; not the dwell time that points remain open, but closed, and how that effects the length of time that current can charge the coil before the points break again and deliver the discharge to the plug.
The lobe on your flywheel is intended from the factory to provide precisely the dwell that results from the points gap. Yes, dwell can be adjusted for performance tuning your bike, but it is a separate setting (resulting from the gap) that should be determined for your application (pipe, kit, plug, etc) and then not changed. Only THEN can you set the timing via rotating the stator plate.
Again, think it through. Changing the gap will affect dwell and timing.... rotating the stator plate changes the timing but does not change the dwell. Which is good. You don't want to change the gap/dwell when timing the motor. Find what's best gap for your bike and keep it there. And then set the timing ONLY with the stator plate.
Or is it me that's confused? (edited)