We recently released a video titled 'Understanding the Different Versions of ROTAX Engines.' This video discusses the two versions of the Rotax 900 series engines and specifies which propeller should be used with each version.
You can watch the video here: https://www.rotax-owner.com/en/videos-topmenu/912-videos/783
We have initiated a discussion in the forum to address any questions you may have regarding the information presented in this video.