S&S Super E

While you carb experts are amassed, can anyone tell me why there is a sweet spot on my S&S Super E with the enrichener just barely raised. It is the airhorn mounted enrichener. I have tried jetting up and down with a little success, but the bike runs best with best idle and all around range with the enrichener just a touch raised. When riding down the road it will purr and sitting at lights it has a nice lope to the idle. It runs good with it down all the way but the idle is higher and not as crisp. Is it possible it needs a jet in between the normal sizes and this is compensating for it? I've asked others and many seem to have the same problem of the sweet spot having to be just a touch raised.Why is this and does it seem to be a jetting problem?

That sounds like an odd one, but could it be possible that you have an intake leak?