I have a 2000 WR400FM, looking through all of the archives here, thumperfaq, motoman393, etc. all refer to the free mod that changes the ignition map from WR to YZ spec as the "grey wire mod"....... Here's the thing, I'm in my garage right now, with my service manual, sitting on the bike, tank off, CDI wiring harness in front of me, and there's only ONE Gray wire in the entire schematic, and it's part of the kill switch, not part of either of the 6 pin connectors, as described in other threads, the other 6 pin connectors have wires labeled as P, Br, W, B, G, R and O, B, Sb, L, Y, B/L (The color code indicates that the G = Green) I read on here the tech. analysis of the CDI unit from a WR250F that the gray wire was a ground, that "told" the CDI to work from the WR map, and when not grounded, it'd work off the YZ map. Now, again referring to the Yamaha factory service manual schematic, the only wire that's connected to ground in any way, off either wiring harness are the wires labeled B = Black...... So thumpertalk gurus, which wire is it????