That is to say that there is a tang that you bend to adjust the float to the appropriate level. I think the manual has a numeric value that they say to set it at (let me know if you need that info and I will get it for you).
No, neither of my manuals (a Chilton, and the origanal, aparently translated by a mad Italian.) has this information. If you do have it, that would be a nice thing to know.