RPM drop and "popping" sound on mag check, C-172

Make sure the plug gaps don't get too large as this will electrically
stress the insulation systems in the plug wires as well as in the
magnetos.


And if you can hit it with the hose while it's running, you can soon tell
what it will do in a good storm!

When the insulation gets rubbed or dirty or cracked, it creates a weak point
where the high voltage will arc over rather than fire the plug. Engines
operated in bush strips will have more dirt build up, and should be kept
clean for safer operation.

Same with a car or bike engine, you want them to keep running when it starts
to rain. Especially if like me you live 22 miles out of town, and have 7
creek crossings that when it rains heavy, it goes up to "F___, that's to
deep to drive through!"

Peter