Ok here it is, I bought a 2007 YZ 450 and wanted an easy fix to hang with the guys who have sponsors and the money to have 6 bikes, I went to my dealer and talked to the main wrench. Here is a cheap(er) key to a white knuckle YZF 1. Go get a Pro Circut Ti-4 slip on 2. Get a Sparks racing TPS Bypass (Throttle Position Sensor) for a YFZ 450 quad 3. A Boysen quick shot pump cover 4. The FMF Stage one jet kit, if you live on the East Coast like me, follow the below 3000 ft settings. 5. And throw in a Twin Air Filter This is a sure way to keep up with those heavy hitters. I noticed a 15 MPH speed increase, way more torque, tons more usable bottom power, and lightning fast throttle response. Snap like a two stroke running lean. Be frigin careful, because this is not a show room floor YZ anymore. TRUST ME!