MORE POWER, MORE PERFORMANCE. The DF40A is the only engine in the 40 HP class to offer DOHC performance, and also the only to incorporate a maintenance-free, oil-bathed timing chain, which provides the outboard with improved durability and maintenance-free operation. With larger displacements for increased power and performance, Suzuki’s Lean Control System improves fuel economy with designs that are more compact and lighter in weight than their predecessors. The new DF40A engines also include the Suzuki Troll Mode System. The Boating Writers of America presented Suzuki Marine with the NMMA Innovation Award for the DF40A/DF50A, during the 2011 Miami Boat Show.