You check that float height yet? That's the only tricky thing about them PWKs man. Betcha it's about 3- 5mm too high. It sounds exactly like mine did when I was tuning my 39mm. When u get it right, it pulls and pulls thru all the gears man. I went from a junk 34mm mikuni to my 39 PWK and once tuned right, it made a HUGE difference mid-top without losing any at all on the low end