Two cylinder, wasted spark application?

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TJones
Posts: 1
Joined: Wed Mar 21, 2007 7:02 pm
Location: PacNW

Two cylinder, wasted spark application?

Post by TJones »

I'm looking for a crank fired ignition solution for a BMW motorcycle and stumbled upon this site. The bike is an aircooled, boxer twin...stock is a wasted spark system with two single output coils wired in series triggered by a single set of points. On my bike in question, the heads have been dual plugged...so, I need 4 plugs/wires. Traditionally, this is done by changing the single output coils to dual output coils...keeping the single trigger (points or aftermarket electronic ignition that functions similarly to the points)...and, wiring the output from each coil to both cylinders (i.e., one coil fires the top plugs on both cylinders and the other coil fires both bottom plugs).

My main question is: if I run the EDIS4, I would run cyls. 1/3 to one side...and, 2/4 to the other. Essentially, the 'compimentary' cylinders would be the same cylinder. So...both plugs would be firing their cylinder on the compression stroke. Can the coils handle that? Or...do they "need" half of the output to be on the exhaust stroke? IOW, I will be making the coils work harder...how will they like that? There would no longer be a wasted spark on a complimentary cylinder.

Thanks-
Terry Jones - BMW Motorcycle

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