A REVOLUTION IN INNOVATION
Over the course of our history in the marine industry, Suzuki has been recognised for having the most innovative new 4-stroke outboards eight times by the National Marine Manufacturers Association (NMMA). This recognition for innovation has also been coupled with many firsts, including the first fuel injected 4-stroke outboards in 1997, the first 250 horsepower 4-stroke outboard in 2003 and the world’s first 300 horsepower 4-stroke outboard in 2006. Introducing the next milestone in our rich history, the 350 horsepower DF350A, Suzuki’s Ultimate 4-Stroke Outboard.
Highest Compression Ratio Ever
In order to achieve the engineering target of producing 80 horsepower per litre from a 4.4L V6 engine, a 12.0:1 compression ratio was employed, the highest compression ratio ever featured on a production outboard engine. To avoid 'knocking' which can be a typical byproduct of a high compression engine, advanced systems were developed to mix cooler air with well-atomised fuel providing optimal conditions for a complete and controlled combustion.
Suzuki Dual Louver System, Direct Air Intake
Suzuki engineers have designed an air intake system that allows the engine to draw in ample fresh air, while separating out water, spray and moisture. Dual louvers under the hood trap larger water droplets and then moisture as it enters the engine cowling, resulting in zero water intake during testing. In addition, intake air temperatures are, on average, 10º cooler than ambient, providing the combustion chamber with cooler, denser air for a more powerful cycle.
Dual Injectors for Increased Cooling and Power
Two, smaller fuel injectors allow for precise injection of fuel to the centre of the combustion chamber, which avoids off-centre combustion – a major cause of knocking. In addition, because 100% of the fuel is injected into the cylinder at once, a degree of cooling is also obtained, providing up to 3% additional power without causing knocking.
The DF350A’s dual propellers provide three key benefits, compact size, increased stability and greater “traction.” By distributing the power of the engine over six blades, instead of just three, the size of the gears and gear case could be kept to a minimum, which in turn allow for a sleeker, more hydrodynamic gearcase design. Suzuki engineers spent many hours in computer simulation and on the water, knowing that reducing drag underwater would be essential to improving overall boat speed and performance. Contra-rotating propellers also provide added surface area, for more stability and increased “traction” or grip underwater. This results in exceptional acceleration, or hole-shot, truer directional propulsion (eliminating steering torque), better than expected top speeds and incredible reverse thrust. Importantly, these benefits are apparent even on heavier boats with full loads of fuel, gear and people.
Advanced Piston Technology
To achieve 350 horsepower, the surface of the piston needs to withstand added forces. In order to assure both performance and long life, Suzuki engineers switched from a standard heat treatment to 'shot peening.' Shot peening is a more expensive process that creates fine dimples in the face of the piston that evenly distribute the pressure created during combustion. In addition, the connecting rods and hardware have been strengthened to handle the added loads.
|Recommended Transom Height (mm)
|X: 635, XX: 762
|X: 330, XX: 339
|Piston Displacement (cm³)
|Maximum Output (kw)
|RON94 / AKI89
|2.29 : 1
|Through Prop Hub Exhaust
|Fuel Delivery System
|Electronic Fuel Injection
|Bore X Stroke (mm)
|98 x 97
|Full Throttle Operating Range (rpm)
|5,700 - 6,300
|Oil Pan Capacity (L)
|Fuel Tank Capacity (L)
|Power Trim and Tilt
|Propeller Selection (Pitch)
|12" - 31.5"