6K feet is about right. By "highest needle setting", do you mean the needle position or the clip position? If you raise the needle, it will come on the main jet quicker (richer at mid throttle). If you lower the needle (raise the clip) you make it come on the main later (leaner mid throttle). The needle really doesn't affect much, just the transition from needle jet to main jet. Changing the pilot and main jet sizes is the biggest change, but most of the Chinese stuff uses Walboro carbs and I haven't been able to find a source of jets. I haven't really tried, though, other than to call Diamo about it and they didn't have any.
Redneck carb tuning (works, but is sort of redneck) is to drill out the jets and use various gauge wires stuck into the jet and bent over the ends so it won't come out to adjust orifice size. First time I saw this, I nearly passed out from laughter, but I'm told it's kinda routine out on the west coast with the flat trackers. Guess they're too broke to buy jets or something.
