Motorcycle Repair: Ignition problem 1992 Ducati 900SS, stator coil, ducati 900ss

Question
Falcon,

Thanks for your input.  In the process of following your tips, I discovered I had the leads from the pickup on the cylinder that was firing backward.  I swapped them and I'm up and running.  Given the way to test the pickup is by measuring the resistance, why is there "polarity" to the pickup?

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Followup To
Question -
After being unable to start my bike, I found there was no spark in the horizontal cylinder and the ignition pickup for the horizontal cylinder was bad (measured open instead of 225 ohms +/5%).  After replacing the set of pickups, spark was restored to the horizontal cylinder and it started.  Unfortunately, when RPMs are increased, the horizontal cylinder drops out ~1400 RPM.  I've verified timing alignment and pickup gaps to the flywheel per my Ducati manual.  I've also swapped ignition modules and coils/wires to verify both ignition modules and coils work on the vertical cylinder regardless of RPM.  With a timing light strobe as an indicator, it appears that with any combination of ignition components (excluding the pickup) the horizontal cylinder spark disappears ~1200 to 1400 RPM (the timing light stops strobing, the cylinder drops out).  It always fires and strobes at idle.  The pickup impedance measures correctly. What should I do next?
Answer -
Hi Jim.
 This sounds like you might have a problem with arcing.  Arcing is where a wire is grounding out only under an operational load.  The likely culprit is the ignition wire or one of the wires going to the ignition coil from power.  You also might want to check stator coil output.  If it is dropping more than the manual allows, then it could drop power to one or more coils depending on how the system is designed.

Try checking that and let me know what you find.
Good luck.
FALCON

Answer
Hi Jim.
 To be honest, I have no clue as to why there is a polarity to the pickup coils.  It could be because of the nature of the way electricity works, or it could be due to needs of the system.  That is more a question for the engineers I think.

Glad that you got up and running so easily.
Have fun.
FALCON