Originally Posted by
Step Turn
If you've tried to battery start a Lycoming, and run the battery down with no success, a hand swing of the prop will no longer work to start it, you're going to have to use ground power .
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This would only be true if you had the Shower of Sparks Mag which are pretty rare, or the STC`d LASAR mag conversions. Virtually all of the small Lycomings are fitted with an impulse mag. These do not require any external power source.
That being said it is not a good idea to use external power if the battery is totally dead. After the engine starts the charging system will provide a very high charging current. This hard on the charging system, can damage radio`s but most importantly is absolutely death in the aircrafts` battery, which incidental will cost a minimum of 250 dollars to replace. With a dead battery the best solution is charge with a good battery charger before trying a start.