761cc
CR31's
Ported w/ 5mm stem kit
CX7 cam 2 degrees advanced (.380/265 @ .040" lift)
You can see John's before and after. He had a big hole in his curve from an over-rich needle (YY6, clip position 1) that was compensating for a lean slide (3.0). (Where the blue/green A/F line goes flat, it's richer than 10:1) Trying to hold speed in a tight corner on the track must have been nightmarish.
Lowering the needle should have cleaned up that transition, but got us nowhere. Then we did a 1/2 throttle 3-7k, 3rd gear pull that was off the charts lean, which was the giveaway. Installing a richer 2.5 slide allowed us to raise the needle and decrease the main jet, and the A/F ratio came back on to the readable scale.
Y7 or YY7 needles and we should be able to flatten out that fuel curve.