Here are some scans of the 1990 Harley FXR Keihin CV carburetor diagrams. These illustrate the general air and fuel paths through the carburetor, showing the general operation of the CV. This might help clear up some confusion many have on which jets and affect what and when, as well as the role of the jet needle.
These pages are from the 1984-1990 Harley-Davidson Official Service Manual, copyright 1989 Harley-Davidson, Inc. I believe these images are posted in accordance with fair-use policy. If you are the copyright holder, please feel free to contact me.