As noted previously, mid-range lean-mixtures got worse with the extra flow. Cruising in and between commuter traffic in the 5000-8000rpm range has more stumbling and jerkiness. Acceleration was also slower in this range.
However, it leaned out the too-rich top-end and the bike just absolutely
SCREAMS between 10000-13000rpms.
Not as fast as my race-bike with 20% increase with full Tyga system, but certainly 8-10% more top-end.
This weekend perhaps, I'll pull the carbs and give it other 1/4-turn out on the pilots and maybe shim needles washer or two. Also remove the noise insert and see if it runs better or worse. I suspect that even with 51mm inlet, the sudden transition steps and sharp edges inside the muffler hampers flow compared to Tyga or Yosh mufflers. It might actually flow without insert similar to those systems
with insert.