pretty sure my issue is the carb body-top, when I spray that with carb cleaner, the moped shuts off (so yeah, giant air leak there). I ordered 3 extra gaskets last night, I'll put em all in, dipped in oil, crush it down. I also ordered a couple of crush gaskets for the exhaust. Once I do that I'll check the rest of them. I have some stiff springs coming in for the clutch, so that should help w/ acceleration and idle issues too. Hopefully w/ the air leaks+clutch, I can idle, get decent accel, and help the top speed. Another big issue, I think my rear hub might be shot, it doesn't spin nearly as nicely as the front wheel. I replaced the rear bearings and grease, and I found the old cone nuts and hub bearing were ground down pretty bad. I don't think I can really fix the ground down hub, so either I need a new wheel or sealed bearings. I might just buy a new rear mag wheel, that seems like the best solution, but I'm still thinking about that one.
I doubt the carb-intake is leaking, I haven't had much of an issue there, but I ordered some of this anyway:
I know the needle only matters up to like 3/4 throttle, and wouldn't be the reason for top end speed. Clutch wouldn't matter there either. Really it's air leaks, gearing, and likely the friction on that back hub.