Thanks, Jack. If I go back to the 120 AC, I can easily walk the main down a jet or two, and that should be fine.
The mid-range is where I'm struggling. It just seems too rich with the BE3, unless it's actually too lean and I've just lost the ability to tell the difference.
That's easy enough to test, I guess; I can throw in a BE1 and see if it's better or worse, just for my own sanity.
I had the 120 stack out for a short (5-6 mile) ride yesterday, most of it at about 50 MPH, lots of up and down hills, so lots of bouncing between high end of 3rd and low end of 4th, because 4th just wouldn't pull up the hills or really rev out, which may have just been the main being too rich. The CHT never broke 200f through any of it, though, so I tried the 140 AC and it seems like a much better fit overall.
I also went back this morning and spent some time re-reading the great
Atomizer Thread, which really only get good at the point I linked, because prior to that, it's backwards.
And, of course, there's always the Mystery Exhaust, which may just not be a good exhaust, but which isn't so bad as to prevent basic performance and which I'm sticking with for the time being. At least it's nice n' quiet.
I'll try to get some comparative videos today or tomorrow. Weather should be nice, but today is already looking kind've busy and my mother-in-law is coming in tomorrow from the UK for a visit, so who knows how that will affect my time.