I'll try to elaborate a bit. Two mags are there to (1) provide a full burn, (2) to produce some power if one fails "redundancy", (3) they work indepently of any power supply/generator/battery, (4)they "should" both work together
Ok; I agree with you that there is more than one reason for having two mags, thought I would disagree as to the order of importance. I said nothing at any point about water, liquid or otherwise. That was mm.flynn
They are timed together but sometimes the timing can drift. I have timed a few mags..... "Some power" is a bit unkind. At least cruise power off only one out of two is an entirely reasonable expectation. Yes, I think we all know that a magneto does not need a battery. I have swung a lot of props in my time. As for coil ignition, we are talking about a typical Lyc/Continental here, rustic agricultural dark ages, so it's magnetos.