Suzuki DF350A 350HP Dual Prop Outboard – Flagship Power with Dual Prop Innovation

The Suzuki DF350A introduces a host of innovations that have made it one of the most award-winning outboards in recent years. Starting with its heart – a 4.4-liter V6 – Suzuki raised the bar by providing the largest displacement of any production outboard, translating into massive torque at all RPM levels. The DF350A runs an exceptionally high 12.0:1 compression ratio, unheard of before in an outboard of this class. This means fuel is burned more completely and powerfully, extracting more energy from every drop – a feat made possible by the dual injectors per cylinder that deliver the precise amount of fuel at two points for perfect combustion. To achieve this compression safely, Suzuki also engineered special combustion chamber cooling and knock control, so the engine operates reliably and long-term despite the high output, giving you longevity along with that raw power.

The most iconic feature of the DF350A is undoubtedly its contra-rotating dual propellers. Instead of one big prop, this engine sports two smaller propellers on the same shaft, spinning in opposite directions. The benefits are numerous: elimination of steering torque (the boat doesn’t pull to one side under throttle), a much smaller gearcase profile (allowing for larger reduction gears to multiply torque), and incredible “bite” in the water. The dual props harness the engine’s power exceptionally well – for the DF350A, this means unprecedented thrust, especially on holeshot or when pushing heavy loads. A boat outfitted with this engine will plane faster and with more authority, and at low speeds the handling (docking, reversing) is significantly improved because the twin props act like two screws biting into the water, instead of one prop trying to swing the stern.

The Suzuki DF350A is built with durability and rough conditions in mind. The intake system features a special two-stage louver system – air entering the cowl passes through a series of curved blades that knock down and trap any water droplets or sea spray before it reaches the engine’s air intake. This means even in driving rain, heavy seas, and salt spray, only dry air makes it into the engine. That technology protects the motor from the potentially catastrophic ingestion of water and ensures consistent performance no matter the weather.

Moreover, Suzuki integrated a dual water inlet cooling system – two points of water pickup (one lower on the gearcase in addition to the normal one) increase water flow through the engine. Even when trimmed up or at high speeds, there’s plenty of cooling water to keep this big engine’s temperature in check, which is key to its longevity and reliability under strain.

The DF350A’s electrical system is also up-sized for heavy-duty needs: the 40-amp alternator can power an array of onboard devices on large boats – from professional electronics (radar, big sound systems) to creature comforts like ice-makers and cabin A/C (though heavy AC use would require running at higher RPM to maintain output). Notably, at idle this engine can already output around 11–12A for charging, and above 2000 RPM it quickly hits its full rating, so your onboard batteries will stay healthy and topped-off.

The Suzuki DF350A comes standard with digital drive-by-wire controls (Suzuki Precision Control), providing silky smooth shifting and instantaneous throttle response. Coupled with the optional Keyless Start System (fob-based ignition), operating this engine feels like handling a luxury vehicle – keyless start and electronic throttle/shift at your fingertips. Another crucial feature, especially for multi-engine rigs, is Selective Rotation – Suzuki engineered the lower unit so that a DF350A can be set to run either standard or counter rotation simply by changing an electronic module and a gearset. This means for twin-engine setups you don’t need a dedicated “left-hand” model – any DF350A can be configured as either, simplifying spares and replacements.

Boats that can make the most of 350 horsepower are typically large center consoles, cabin offshore fishing boats, or performance hulls in the 8–10 meter (25–33 ft) range. A single DF350A can propel a 25–27 ft boat to impressive speeds (over 45 knots in many cases, depending on hull design). Many owners choose twin DF350As for 30+ ft offshore boats, giving them a total of 700 HP and the peace of mind of redundancy (twin setup ensures you can still get home even if one engine has an issue). Triple or even quad installations of these engines are not unheard of on big 35–40 ft center consoles in the U.S., where extreme speed and carrying capacity are demanded. Thanks to the dual prop design, even with multiple engines, there’s no need for special counterweights or fancy steering compensation – the boat stays true and stable upon acceleration.

The Suzuki DF350A has earned prestigious awards like the IBEX Innovation Award (2017) for its contra-rotating prop system and overall engineering excellence. With this engine, you’re getting Suzuki Marine’s pinnacle of technology – a combination of brute power, smart efficiency solutions, and modern conveniences. If you’re looking for an outboard to drive your big boat with authority, maximum traction, and control, the DF350A is among the best in the business, built to handle the seas day in and day out.