Troubleshooting Magnet (points) Ignitiions
While looking around for something else, stubled across this pdf that has everything you ever wanted or needed to know on troubleshooting magneto ignitions. Along the way it also touches on checking the battery and connections.
Obvioiusly you don't have to have a Fluke meter, and while it's directed to "outboard" ignitions can be used for any small engine.
Here is a link that might be useful: Magneto Ignition