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Old 03-30-2013, 06:53 AM   #4236
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Joined: Jul 2007
Location: Garden City, Michigan
Oddometer: 3,649
Originally Posted by XDragRacer View Post
DirtyDog has a GENERATION 1 KLR650, GAS GUY, with a CDI igntion. The primary ignition coil windings of the Generation 1 bikes are pulsed with considerably more voltage than the 12 volts you suggest.

The Generation 1 CDI's are powered from alternating current from the stator exciter coil; this AC is stepped up to maybe 100 volts or so inside the CDI (the "igniter" component), this voltage is rectified, and used to charge a capacitor.

When the timing mass on the rotor passes proximate to the pickup coil, a thyristor discharges the capacitor's 100 or so volts through the ignition coil's primary windings; this voltage is transformed many times higher by induction through the ignition coil's secondary windings, firing the spark plug.

The Generation 2 ignition, by contrast, saturates the ignition coil primary windings with 12 VDC; interruption of this current induces a high voltage in the igntion coil secondary windings from the collaps of the electromagnetic field created by the saturation.

More simply put, Generation 1 KLRs have Capacitive Discharge Ignitions; Generation 2 KLRs have Inductive Discharge Ignitions, "fully-transistorized breakerless ignitions," as Kawasaki marketing prose would have it.

Thanks for the clarification on the cdi.I have never had to actually test one and assumed they were like other recent automotive systems.
I had no idea that kind of voltage was sent to the coil.

I'm looking at a Gen 1 wiring diagram in a Clymer manual and that same black wire that goes from the Cdi to the coil also splices off and goes to the tach.

So the tach gets 100 volts ?

And if it does, wouldn't DD's tach read while cranking, if he is in fact getting the make and break signal at the coil from the cdi ?
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