Ok.....so I took my shee to be dynoed and tuned. I watched the guy do it and he did not use a carb sync tool. He said with the dyno he did not need one, as a matter of fact he kind of laughed at the notion of using one. He says theres more to the sync then just the vacuum . He seemed to know what he was talking about, so I let him do his thing. When I took it home she was screaming. Running perfect. When I put the carb sync tool on the carbs the vacuum was way different on the two. So I adjusted one of the slides to match the vacuum on the other, and it sounded like shit so I put it back to where it was, and it sounded great.... So I guess I Am just a little confused on What's happeing here....