6v or 12v coils

[olympus]

Would appreciate your views.. pros & cons etc.
Stay with 6 volt coils or change to 12 volt
2x single coils or single coil with two leads

 

[baz]

If its electronic ignition Two separate 6volt coils are best according to most things I have read

 

[Fast Eddie]

With what ign ??

 

[kommando]

No difference between 1 twin outlet 12v coil and 2 single outlet 6v coils of the right total resistance, the one to avoid is 2 single outlet 12v coils.

 

[1up3down]

Well, CNW supplies their Trispark EI with their single 12 volt coil set up with resistance plugs
which I have been running for the past five years perfectly

 

[kommando]

2 single outlet 12v coils are not the same as a single twin outlet 12v coil. The 2 single outlet 12v coils have double the resistance of an equivalent of a single twin outlet 12v coil.

 

[Fast Eddie]

Well, CNW supplies their Trispark EI with their single 12 volt coil set up with resistance plugs
which I have been running for the past five years perfectly

I did the same as you, bought a Tri spark, coil and leads all from Matt. That way you know your getting a fully compatible system.

One less thing to worry about !

 

[baz]

Sorry just looked at the the thread I posted I was advised on here not to use a double pole single coil with Lucas Rita ignition because the Lucas keeps the coil on for too long and a single coil can't lose that amount of heat, cheers

 

[Fast Eddie]

Sorry just looked at the the thread I posted I was advised on here not to use a double pole single coil with Lucas Rita ignition because the Lucas keeps the coil on for too long and a single coil can't lose that amount of heat, cheers

That’s interesting. And probably explains why my mate burned out a rather posh, rather expensive, Dyna coil with his Lucas system...

It also reinforces my desire to go with a ‘known quantity’ for the whole system. Unless you really know what you’re doing (and I don’t), it’s just way too easy to make an innocent error like my mate did.

 

[baz]

What ignition do you have Olympus?

 

[baz]

That’s interesting. And probably explains why my mate burned out a rather posh, rather expensive, Dyna coil with his Lucas system...

It also reinforces my desire to go with a ‘known quantity’ for the whole system. Unless you really know what you’re doing (and I don’t), it’s just way too easy to make an innocent error like my mate did.

Any idea what ohms that coil was? Was it mounted on a heat sink? Cheers

 

[olympus]

What ignition do you have Olympus?

Boyer Mk1V.... also looking at their power box coil option

 

[Fast Eddie]

Any idea what ohms that coil was? Was it mounted on a heat sink? Cheers

Don’t know the ohms. Yes it was mounted to a heat sink, perhaps it was good enough or mounted correctly? Too long ago to know!

 

[L.A.B.]

Boyer Mk1V.... also looking at their power box coil option

A Boyer "Powerbox" is a regulator/rectifier. Micro-Power mini-coils cannot be used with anything other than the Micro-Power ignition.

Boyer MkIII/MkIV instructions:

With this system two 12 volt coils can be used [in series] as long as they are in good order. The standard 6 volt coils do short out to the metal case, check for damage by the mounting clamps. A single dual output coil can be used as long as its primary resistance is more than 3 ohms. This should be mounted on the frame in a manner that will take the heat from the centre core.

http://www.boyerbransden.com/pdf/COIL00004.pdf

 

[olympus]

A Boyer "Powerbox" is a regulator/rectifier. Micro-Power mini-coils cannot be used with anything other than the Micro-Power ignition.

Boyer MkIII/MkIV instructions:


http://www.boyerbransden.com/pdf/COIL00004.pdf

I stand correct sir...should have put my glasses on.

 

[Madnorton]

Realistically these days, 6V or 12V coils on a Commando is much 6 of one half dozen of the other. Providing the system is wired correctly and connections are all clean and tight, decent rectifier and battery, then both should should perform well.

Most electronic systems these days are also a lot kinder to the coils by using clever switching and control of power to the coil, unlike the days of a contact breaker.

As LAB and others have pointed out some systems, need specific coils to function, check when you buy the system.

 

[MikeM]

How do you identify whether the coils are 6 or 12 volt? I am using the old points style ignition.
Sorry but I am electrically challenged.

 

[L.A.B.]

How do you identify whether the coils are 6 or 12 volt? I am using the old points style ignition.

A typical 6V coil would have a primary resistance of approximately 2.0 ohms. A 12V coil would be approximately 3.5 ohms.

If original Lucas, then a 6V coil will be marked 17M6 on the base of the coil and 12V is marked 17M12.

 

[74ok]

the stock original 6v dual coil setup also runs/works with a ballast resistor
(dunno what year this started)

http://rocbo.net/technique/norton_workshop/086.html

tho apparently not required with boyer

https://www.oldbritts.com/simp_wd.html

68 went 12v & pix shows 2 6v coils wired in series with tri spark
Broken link removed