RE: Props for YS 91 AC
Your translation is fine, we can understand it.
I had one of my YS 91 AC engines on an acrobatic plane that was not a 3D or Pattern aircraft. I used a wide blade 14x6 Taipan or Graupner prop that worked very well. The plane was 3700 grams (8.1 pounds) with fuel and the engine pulled it around with excellent authority. It did have unlimited verticle but it was not a hover type plane so I do not know if that prop would have been suitable for it. As I remember, the rpms on 20/20 fuel were well over 10,000.