All modern circa 1980 and newer bikes, quads, snowmobiles etc use a CDI to supply the momentary electrical current / voltage to the coil subsequently firing the plug. Where and how does the mystical "Black Box" get the timing and power to do its work? First: There are two power sources that charge the capacitors that will eventually discharge into the coil. 1.The older of the two is an AC voltage provided by a coil located (usually) on an arm of the stator complex inside the engine 2. A newer source is a 12V DC voltage provided by the battery. (There is circuitry inside the CDI that changes this into the high voltage needed to fire the coil. Next, there is a trigger coil (Sometimes a Hall effect sensor) that sends a "triggering Voltage" to the CDI to tell it to release the stored energy in the capacitor. OK... So what? In the decades I have been working on bikes and quads, the above mentioned system has always been a guessing game to diagnose. Most service manuals give resistance specs for the charging and triggering coils, BUT I, as well as others have replaced these parts that were out of spec only to have no resolution to the issue... WTH. For the last few years I have been testing the resistance of ALL the source and trigger coils of machines that come into the garage for any type of repair - usually carb cleaning. I would say, about 25% have out of spec values but were running just fine. My request (for the curiousness of it) and to help others, is for those that feel comfortable measuring these values on their own bikes and post it up so I can distill it into actual data.