One thing not mentioned in that link above (although it's in the ST instruction leaflet) is that the ST carb has a midrange adjustment if the idle mix doesn't fix the transition problem. There are two screws holding the fuel inlet spray bar where the main needle screws in and by loosening these two screws you can rotate the whole assembly to alter the angle the fuel nipple points. This is quite convenient for getting a neater run of the fuel tubing but it also happens to be the midrange adjustment! ST recommend starting with the nipple pointing straight at the front mount hole (this is basically how it's set from the factory). Rotating the nipple up leans the midrange and rotating down richens it. Don't forget to tighten the two screws after making an adjustment.