Well, Couldn't find any old threads on this theme; only IDA'S have been discussed?
Redline, Braden and Passini (on 40IDF 10 and 11) says this on float setting: Closing at 10mm depth, maximum opening at 32,5 mm float height.
http://piercemanifolds.com/Float_Level_1.htm
Does anyone know if this applies to ALL IDF models?