I have a 191FS with a Suzuki 140 HP engine currently running with the supplied 3X13X21 aluminum prop. Max. RPM reached is 5000 (WOT), with a speed of 35 MPH (GPS). Boat had 1/2 tank of fuel and 2 adults and 4 young children aboard. Specs. say engine should top out at 5600 to 6200 RPM at WOT. Adjusting the trim made no significant difference in WOT results. Anyone running a different prop care to share their experience?