I have been flying my 180FS conversion some more (WT38 carb fitted) and have noticed that a much lower idle is possible by leaning the bottom end needle. This results in a poor transition/cut on opening up. To get a reliable idle and transition, the low end is really rather too rich.

Can I make any adjustment to the throttle plate or pop-off pressure to richen the mid-range? Top and bottom have plenty of adjustment as it is.