Here's the skinny on the whole green wire debacle, explained by a knowledgable friend of mine:
The newer blaster CDI (2003 +) has a separate ground coming from the source coil (the one that generates the power for the spark) to help "clean up" any noise (electrical interference) that could cause the CDI to not time the spark correctly. On the older stator plates, the "positive" wire of the coil goes into the wiring harness (the black and red wire), and the "negative" wire goes to the stator plate (to act as the ground).
On the newer ones, the green and white wire is the ground for the source coil run into the harness. You can (with relative ease, a soldering iron, and some patience) turn a 4 wire stator into a 5 wire stator without too much headache by snipping off the ring terminal of the ground wire, soldering on a loose ~18 gauge wire, and running that wire out through the wire loom with the rest (make sure to tuck it in properly with the rest of them, so that it won't get caught in the flywheel!), and putting a "bullet" connector on the end to plug into the harness.