I have a YS 91 AC, installed in a BRAVADO F3A ([URL]www.acrobatico.com.br[URL]), that is with one weight of 4005 grams. Currently flying in Brasil. Already I tested some type of props. Between them APC 13x12(-----RPM), 14x10(8500RPM) and 14x8(9700RPM) and the flight of it was not good, summarizing, was very fast in level flight and with poor force during the ascents. To know of the reached friends whom this exactly motor also has the RPM's with these props and with others for example, APC 15x6, APC 15X8, APC 14x6, APC 13x11, APC 13x13, APC 13x14, APC 14x12, APC 14x10, APC 14x14, Thank´s so much for help.

P.S.: Always run with WildCat Fuel 20/20

Are you looking for speed or pulling power? If you are looking for speed, then try APC 14x9. If you are looking for torque, then try APC 15x6 or 15x7. Keep your static rpm above 9200.

Hi Richard, all good one? I am looking torque for my model, therefore it was a little heavy for my engine, then I have that to have more torque of that speed, the ideal would be that it had the weight of 3600 - 3700 grams. In the last end of week I used to wooden propeller Zinger 15x6 and the result was very bad, the engine turned little and was without force. Perhaps this bad performance is explained why this prop is not appropriate for my engine and all we know that they do not exist propellers that the APC's. I go to try 15x6 and also one 13x11. Thank´s for the help.

OBS.: I´m using the tool of translation of languages of the Google. You it understood everything that I wrote?

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.

If you are looking for more torque, then try APC 14x6 or APC 14x6W (wide blades). APC 15x6 should also work. APC 13x11 produces a lot of speed but little torque, so it will not work well for you.

We can understand your translation just fine.

I'd try a Zinger Pro 14-8, or a K series wide blade 14-8 Master Airscrew.

Staff, I looked to prop APC 14x6W but I did not find here in no store in Brazil. I also obtained only the normal APC 14x6 and APC 15x4W. There are some difference between the two? the props with wide blades are better? Thank´s...