Boyer ignition coil wiring ?

Am trying to work out why, the two 12 volts coils are wired in series on a twelve volt system ?, shouldn't they be either:

Two 6 volt in series, or,

Two 12 volt in parallel ?

If you are referring to the Boyer Bransden MK3 electronic ignition, you should be using 2 X 6 volt coils wired in series, and this utilises the original coils that are fitted to Nortons.

http://www.boyerbransden.com/pdf/KIT000 ... 00017_.pdf

Reggie said:

If you are referring to the Boyer Bransden MK3 electronic ignition, you should be using 2 X 6 volt coils wired in series, and this utilises the original coils that are fitted to Nortons.

http://www.boyerbransden.com/pdf/KIT000 ... 00017_.pdf

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Josh's Commando is a 1970 model, so it would have had two 12V coils (and no ballast resistor) originally.

Both Boyer Bransden and Pazon say that two 12V coils can be used in series provided that engine compression isn't too high, but the spark energy from two 12V coils in series will not be as good as two 6V coils, so it would be better to fit two 6V coils, or alternatively fit a 12V dual plug coil.

Rhanks,

LAB, what of wiring the two in parrallel ?.

Is the capacitor still fitted with the boyer ?.

Josh Cox said:

what of wiring the two in parrallel ?.

Click to expand...

That's not recommended.

Josh Cox said:

Is the capacitor still fitted with the boyer ?.

Click to expand...

If you mean the blue 2MC ignition capacitor, then there's no need to remove or disconnect it.

If you mean the blue 2MC ignition capacitor, then there's no need to remove or disconnect it.

Click to expand...

However, it is not necessary to retain it. If the capacitor is in good condition ( a big 'if' for a 40 year old capacitor) it is possible to start the bike with the Boyer and a flat battery, but if the capacitor is weak or leaking or otherwise will not hold a charge why keep it?

I have not seen one actually short out to cause problems, but have seen them that simply won't hold a charge to start the bike.