I'm installing a Z-start auto clutch on my 03 CRF 450 I race motocross and will give you some feedback after my race on 1/11/04. From all my research I'm sure it will be positive. For more info go to www.rekluse.com and click FAQs.
I have one on my CRF and love it. No stalling, never in the wrong gear, start in gear, no need to gear down for woods, holeshots every time, better traction/less tire wear, easy install and adjust! What's not to like?