I tried the 11/6 today and it did reduce the power output. The plane was not as responsive from 1/2 throttle to full and at 1/2 throttle it flew slower with a tail down attitude. On the second flight I went back to a 10/6 and the ST 45 opened up with more power and quicker from 1/2 to full throttle. I will stick with the 10/6 .Thanks for your comments. Testing did help but your input was interesting.