6 volt coils, why?

Something I've never understood, and have always been a bit curious about, is why Norton fitted our Commandos with 6 volt coils and a ballast resistor. The literature says it makes for easier starting with a run-down battery. But why would that be? Could someone explain that to me? Inquiring minds want to know.

Or is the truth simply that Norton had a warehouse full of old 6 volt coils to use up???

just wondering,
Debby

The explanation I received goes something like this... less is more. Higher resistance = weaker spark and Boyer its limits.

Total resistance should be around 3 -6 ohms ( for the Boyer).
6v coils are around 1.6 - 2 ohms each, 12v around 3.5 - 4 ohms each.
So, two 6v coils = 3.2 - 4 ohms, two 12v = 7 - 8 ohms. Keep the Boyer Gods happy with 6v coils.
Unless you've got that rare diesel Interpol prototype. :wink:

Fstbk

:roll: