Last night I followed this guide I found on the internet http://waynescyclegarage.mysite.com/custom.html showing you how to rewire a Honda SL engine so that it can run without a battery.. and I got it sparking any everything, everything works fine, but in that guide it also says that I can't use a DC coil with this setup or it might damage the piston or something.

I don't understand why that would be. Isn't a spark on a spark plug just the same whether you use a DC or AC coil? A spark is a spark, isn't it?

But if I'm missing something and it turns out to be true that you do need an AC coil or there will be damage, how can I find out whether my coil is a DC or an AC? Because I never knew, it doesn't even say on the outside of the coil.

Actually, I just realized that this guide is on 2 sites on the internet (written by the same person though) but in this version of the guide http://forums.sohc4.net/index.php?topic=43403.25 it says this: "Your bike will crank and run with the original DC coil but do not be tempted to ride it! It can cause major engine damage like holes in pistons.The AC coil is key to this mod.Now what do I do with all that extra room where the batt and rectifier went? I'll think of something."

  • What AC coil are you considering? – Solar Mike Jul 26 '18 at 8:42
  • I don't know yet.. first I'd like to know if this guy is right that I actually need an AC coil and not a DC. – Arnie Cunningham Jul 26 '18 at 8:45
  • Well, how about finding out if your bike is producing AC or DC and where... – Solar Mike Jul 26 '18 at 8:46
  • Well it has an AC generator (rotor and stator)... but that doesn't necessarily mean that the coil is an AC.. it could be anything. – Arnie Cunningham Jul 26 '18 at 8:48
  • So, what tends to be the next component after the rotor and stator? – Solar Mike Jul 26 '18 at 8:50

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