I can't think if I've ever seen this be done with the L on the left and theR on the right. Even on my Rotax 914, which is, *ahem*, modern and doesn't have magnetos, the key is still labeled with R on the left and L on the right.

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    $\begingroup$ I am certain that this has been asked before... $\endgroup$ Dec 7, 2023 at 2:09
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    $\begingroup$ @MichaelHall I thought so, too, but hadn't found it. I'll give a more thorough look. $\endgroup$ Dec 7, 2023 at 2:46
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    $\begingroup$ Possibly related question $\endgroup$
    – ROIMaison
    Dec 7, 2023 at 8:26

1 Answer 1


This website gives a good explanation which I'll repeat here.

But… deep breath… selecting the right-hand key position grounds out the right mag, essentially turning it off, while leaving the left mag running — so the right key position is marked with an “L.” Likewise, moving the key to the left (but not all the way to OFF) now disables the left side, leaving the right side working — hence the “R” label at the left key position.

Key position dictates what’s “off,” while the label shows what’s on. So there is a certain logic to it, once you embrace it.

For a more detailed explanation see the website itself

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    $\begingroup$ But the "Both" and "Off" on OP's picture relate to what's on, right? $\endgroup$
    – jcaron
    Dec 7, 2023 at 15:09
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    $\begingroup$ OFF means both mags are grounded out and won't work. R means the left mag is grounded out and only the right one works. L means right mag is grounded out and only the left one works. $\endgroup$
    – John K
    Dec 7, 2023 at 15:41
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    $\begingroup$ I read this as, "somebody crossed the wires, changed the labeling to match, and it became standard". Explains things, but doesn't make sense. $\endgroup$
    – FreeMan
    Dec 7, 2023 at 17:50
  • $\begingroup$ @FreeMan if I had to guess, it's because the rotary switch is the evolution of the fliip switches, avcanada.ca/forums2/…. In those cases, flipping the right switch turns off the right mag. So it's a perfect mapping, although that doesn't mean it makes good sense, even if it makes sense. $\endgroup$ Dec 8, 2023 at 4:15

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