That's upside down. The bottom of the bowl pushes against it to keep the main jet in the carb body. Then measure from the highest point on the float to the o-ring sealing surface on the carb body. The tang on the float that makes contact with the needle is what your adjusting. Everyone's a little different about contact, but my practice is, the height is measured just as the tang begins (makes contact) to compress the needle. I thinks its like 21mm, but dbl check the manual, in the end you'll need to clear tube them to verify the fuel level in the bowl, preferably before you install, its just way easier that way.
