25 was a lot in 1929 for an outboard. The ‘29 quad was the second highest rated motor only beaten by the 1929 Johnson V-45 making 26hp. Keep in mind that is for non-racing motors. Elto/Evinrude didn’t rate their racers, but the racing Johnson VR-45 was rated at 32 from the factory. The 29 quad used a metal impeller not to dissimilar from rubber impellers. It was also the first to implement that type. The year before it used the prop wash to push water through the system.