I had an opportunity to get my dads 85 xr600 running, and it was fun seeing just how different the crf and xr motors are. the caps for checking the valve clearance and the set screws for adjusting them are awesome, would be sweet if the crf had that capability. do you thin that if somebody developed a valve cover with removable caps, and rocker arms with adjustable screws for the x that it would work out? you would probably need different valve springs to accommodate the the extra mass of having a setscrew and jam nut. would be nice to do away with the shims, and having to take the whole shebang apart to change them. i know, LAZY. i love working on bikes so it really doesnt bother me, it just got me thinking. what do you guys think?