I read the wiki on diesels, and I think I read that if a diesel is running,
then it doesn't need a spark (e.g., battery energy) to keep running. If
that's the case, then it seems like you should be able to start a diesel by
hand, assuming you have the muscle or leverage. So, in the former case, even
if your battery died - perhaps got wet and shorted out - then the engine
would keep running. In the latter situation if the battery was already dead,
you might be able to crank it to start it.

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