Okay. I took a gander at the sprocket. No holes. So that got me wondering, and I called up the local motorcycle shop. They mentioned it could either read off of the sprocket or the sprocket nut. So I did a google search and on zx6r forums they show little marks on the sprocket nut that are meant for the hall sensor, which i'm assuming is another name for the speed sensor. So I gotta know, is it the sprocket or the nut that the speed sensor reads off of? I see sprockets all over with holes and some without. He did mention it could be backwards and there could be a strip with magnets in it on the sprocket that could do the signals. I'm really confused here! Even his dealer book didn't show what did the actual signaling for the speed sensor.