8 plug head ignition query

[Robw]

I will be getting my modified head back soon and have a query with the ignition side of things. I will be fitting green Dyna coils, which match the ones already fitted.
The query is how are they wired is it just a matter of splitting each wire to the coils and connecting them in the same order as if the head had single plugs.
Cheers Rob

[zed1015]

You need four 1.5 ohm dual output dyna coils ( the ORANGE ones ) with each pair wired in SERIES so what you end up with is the equivalent of two four output 3ohm coils and set the timing at 35 deg full adv as a starting point.

[Robw]

Cheers for the info, could they be put in parallel as well, so that each coil (3 ohm) ignites the same plug as if they were standard. Just trying to get my head around the iginition side of things, never have liked the electrics.
Cheers Rob

[pertonpc]

Hiya Rob,

Don't know if this will help but the Zephyr 1100 runs an 8 plug set up from the factory so if you can skank a look at a haynes book or online forum for that bike they will know all about how 8 plugs work (don't imagine that there are 8 coils!!!)
Cheers from Mark

[zed1015]

Don't wire in parallel, It won't work. You will get a spark at only one coil or the other which ever offers a path of the least resistance. Also when fitting the HT leads don't put both leads from one coil just to one cylinders plugs. Say cyl's 1 and 4 should have one HT lead each from their pair of coils. That way if a coil fails you don't totally lose spark to either cylinder.

[Robw]

Cheers for that, never were any good at electrics that's why I trained as an Aircraft engineer and not Avionics. As you said about the plug leads I will wire them the same way as they are originally.

Rob

[zed1015]

Here's a diagram of the wiring and plug lead configeration for 1+4 (same for 2+3). You only need a simple link wire for each pair of coils so no need to chop the harness.

[Robw]

Cheers for that it will help a lot

Rob