using single coils in parallel possible?

Hello, Wonder if you could use 2 single coils from single cylinder bikes connected together to fire 1-4 or 2-3 on a KZ1000? I have a bunch of coils from single cylinder breaker point mcycles and would really appreciate any input if this would be possible. Thanks:)

i can't see why it would not work, hardest part I see would be mounting them.
pic is of Wayne Rainey's 1983 superbike. it was dual plugged with four coils.

Well I'm sure you could do it, but first and foremost Why bother when there so cheap for the right coils. I got two complete coils with brackets off Ebay for $25. Just bolt EM on and ride. Other wise you are doubling the resistance of the primary windings, AMPERAGE load on the electrical circuit. If you have the electronic system the coil resistance was lower than the points system from Ma Kaw. So you might be able to hook it up and make spark, but will it last/ miss fire at RPM/ burn up Ignitor box/ or wiring. You may be able to use another ignition box as MSD makes to supply both coils on one set of cylinders, it makes it a RELAY station so to supply addition B+ to fire the coils.
Still say shop Ebay and run either a good aftermarket twin fire coil set or stock. Good, cheap and reliable.

Z1 sells new OEM equivalent 4 Ohm dual output coils for $36.

Four single coils would double the current load on the wiring and probably pop a fuse.

Besides the extra current as Bountyhunter mentioned, there is another problem.

When the points open, the two coils in parallel form a closed circuit. Since one is firing through low-pressure exhaust, and the other is trying to fire through 10:1 compressed air, the exhaust-stroke spark plug will fire at a lower voltage. Once it does that, the primary current of the other coil has a low-voltage path to dissipate current through. This means the energy for the firing cylinder's spark plug is going to dissipate in the spark plug (and coil) of the cylinder on the exhaust stroke.

If you get sparks at all on the compression cylinder, I think they would be weak.

You would need a way to isolate the paths of the two coils. You could use high-voltage/high-current diodes to do it. They would have to be like 1000 piv, 5 amp diodes. You would put one diode in series with each coil.

Thanks for your inputs. would just like to tinker around and learn. The info from these mods and conversion might be useful someday. would be trying Loudhvx's suggestion. Can I use this coil set up with your GM HEI mod?

jeffreygp wrote:

Thanks for your inputs. would just like to tinker around and learn. The info from these mods and conversion might be useful someday. would be trying Loudhvx's suggestion. Can I use this coil set up with your GM HEI mod?

Yes, it shouldn't be a problem, as long as the coils are the typical 4 ohm range. To be safe you would use one HEI module per coil, but you could try the two coils in parallel with the diodes too. The resistance will be a little on the low side, so the HEI modules may heat up a little while they limit the current. Due to the current limiter, the coils won't be getting full power if they are in parallel, but it should probably still work fine.

I know with some of the Dyna Ignitions like the Dyna 2000, Dynatek has a 4-coil wiring setup for twin plug heads. This involves putting coils in series. However, each coil needs to be HALF the resistance... Dyna uses two 1.5 ohm coils in series when 2.2 or 3.0 ohm coils are usually used.

I'll be experimenting and post developments if it works out. thanks so much guys.

Yes, two coils in series should work since breaking the ground connection leaves no complete paths for either primary. As Jeff Saunders said, you have only to consider resistance then.