I use a black Master Airscrew 8x6 prop on my little OS .10 FP that turns 10,500 RPM, two oz tank and 36 oz all up weight. Very good power! It is quiet with 21 inches of pipe to the rear of the plane and I did not remove the OS muffler mute. This long pipe means no mess and it only costs 200 RPM This plane is covered with Ultra Coat. A mini gyro is required to tame the strong ground looping tendencies of this aircraft.
