How do you test a coil on Briggs?

Safest wsy is using a spark tester. Some look like a spark plug with a clip on it. You connect the coil wire to the tester and clip the clip to the engine. Try starting the mower and watch for spark. The other way is to expose the metal end of the plug wire, and hold it close to the engine, while someone tries to start it. But be warned, that way isnt the best and will give a nice shock.