hohoho...
after more ivestigating,here's what i find..
here...http://microlighters.co.za/viewtopic...6fb17ec0137cbc
912S and late model 912 80 hp 75 mm flange pattern for Ultrailght model propeller bolt holes are not threaded
so we use the stronger AN5 BOLTS,
so my flange are not thread (early model)
maybe AN5 is my option...
what do you think gentleman
Jf