I just wanted to post a follow-up with the issue I was having. Upper RPM after the secondary carb kicked in, the engine would break up and bog, badly. I installed a Rick's XR600R CDI, and while the bike started and ran much better than before, the problem was still there. At this point, being at whits end, I took the carbs off again. As soon as I removed the bowl from the secondary carb, I found the problem, laying there, as if to laugh at me, the main jet! I swore up and down, that not only had I had the carbs off, rechecked everything, but maybe I didn't. Admittedly, I've taken many shots to the head over the years, and probably mixed up which bikes I was working on, and which carbs I had off. Too many projects. So anyhow, after re-tightening the secondary main jet, the bike fired right up!
Moral of the story is this, never be a fighter for a living, because you will loose your marbles...or main jets.....