John,
Rotax specifically states to use a propeller with a Mass Moment Of Inertia (MMOI) that is below 5800 kgcmcu or premature gearbox failure will occur. Other causes to premature failure include low idle speeds, improper oil, exceeding oil change intervals and I am sure there are others.
The only propeller manufacturer that I know who posts MMOI is Sensenich, there could be others but I haven't seen it. I am now running a 74.8" Kiev and sent Kiev an email prior to installation requesting the MMOI, they responded with 4700 kgcmcu.
Search MMOI in this forum and you will find links to an EAA video and other information on the subject.