Propeller Replacement Propeller Dia (In.) 27 in Bore Dia (In.) 3/4 in Number of Blades 6 Pitch (Deg.) 25 Degrees Blade Material Spark Resistant Cast Aluminum Keyway (In.) 3/16 Number of Set Screws 1 Rotation CW Facing Discharge Required Motor HP 11-1/22 Required HP @ Higher RPM 2 hp Required HP @ Lower RPM 1 hp RPM Low 1 400 RPM RPM High 1 850 RPM Max RPM 1400/1650/1850 CFM @ 0.000-In. SP 7900/9315/10 440 CFM @ 0.125-In. SP - CFM @ 0.250-In. SP - CFM @ 0.375-In. SP -