I've already done a search and it's seems most people feel the XR600 redlines about 7500. I've had mine to 7400 and it sounds like things want to come apart,and power is already falling off. I've also found that people say the 650L which I always thought was about the same engine redlines at 9000 and some have had them to 10000. I've been playing with carburation and just want to know if I should be looking for more RPM to be sure it's running clean. The Edelbrock site shows max HP at 7000 and a sharp drop after that It also shows it making more HP then a XR650R so I don't know how accurate that is.I should mention that I've got an HRC cam and H.C. piston and E2 exhaust. I don't intend to run high RPM much just want to know that I've got it setup right.