Quote: The power valve being open will not contribute to rich idle mixtures.
If you have a rich idle mixture, your screws simply are too far out or your manifold vacuum requires the idle stop screw to be cranked in so far that you are drawing too much fuel from the transfer slots. This is a common problem.
Take the carb off and look at the primary throttle plates and look at how much of the transfer slots are exposed. Or take a pic and post it.
Bullit, once you confirm your float levels and make sure your idle mixture screws aren't screwed out too far, look at what CKJ440 said, and re-read what I wrote about transfer slot/throttle plate relationship in your other thread. There's a good chance it'll fix your problem.
