Rotax have progressed the 912 steadily with the 914,915 and now the 916 all on the same basic platform with enhancements were required. Lycoming did a similar thing with the O-235 then O-290,320,360 and finally IO-390.
Both engines have flying web crankshafts, 3 main bearings for a four cylinder. Must be a good idea?
Rotax 9xx engines have nothing to do with their other BRP products.