CHARACTERISTICS

Compression Ratio
The solution to developing 74bhp per liter from a 350bhp V6 engine was to increase the compression ratio to 12.0:1, the highest compression ratio ever for a production outboard engine. To make this work without knocking (a typical problem in this ratio), we developed systems to mix cooler air with fuel injection to provide optimal conditions for complete and controlled combustion.

Direct Air Intake and Special Intake Louvers
At high velocity, water particles could be directed, trapped and drained.

Our experienced engineers worked to put this theory into practice by increasing the intake flow to convert water vapor into particles and designing the vanes to capture and deflect these particles away from the intake flow. The Dual Louver system incorporates double blade shielding. The outer row of blades removes the spray from the boat and the inner louvers capture and drain the remaining mist.

As a result, the air is free of moisture and its temperature is no more than 10 ° above the environment.

Dual Fuel Injectors
Fuel injection does two things, it sprays the fuel and "cools" the cylinder to minimize knocking. To achieve the power we wanted, we needed to inject 100% of the fuel into the cylinder at the same time, at a precise time and at a precise angle to cool the cylinder and to allow combustion in the center of the combustion chamber.

The new dual-injector system using two smaller injectors provides the required precision as well as improved atomization, increasing performance by 3% without causing knockback.

Reverse Propeller Rotation
The counter-rotating propeller provides more underwater "grip" and because the counter-rotating props distribute the engine torque evenly across two propellers, the torque per propeller is reduced and the gear diameter can be reduced. This makes it possible to reduce the diameter of the gear, which could lead to the design of a smaller and more hydrodynamic gearbox.

Special Propeller Blade Design
A new front / three-blade propeller arrangement has been developed which provides improved performance on the water. This new setup not only provided the highest recorded speeds for the DF350A, but delivered incredible acceleration, even under heavy load and at high revs.

Double Water Inlet
On the DF350A, the best results were achieved when the main water intake was mounted at the front of the gearbox case, with the secondary water intake directly above the frame. This was our final solution to placing the main and subassemblies as far apart as possible and designing them to ensure a reliable amount of cooling water, especially at high speeds.

Designing a Stronger Push
Gear material was changed and heat treatment added to withstand the added thrust and inertial mass from reverse thrust, which was stronger in a counter-rotating propeller. In addition, the reverse gear was moved above the cavity plate and the position of the lower engine mounts was modified from parallel to V-shaped to accommodate the reverse gear above the cavity plate.

Better Directional Accuracy
Better Directional Accuracy

Normally, when multiple motor installations are used, a combination of standard and counter-rotating motors is assembled. Suzuki Selective Rotation, available on AP Series outboards, eliminates the need for different models as any model can be easily programmed to run in any direction. The DF350A's counter-rotating propeller technology takes this process one step further by eliminating steering torque and maximizing true and equal thrust forces.

CHARACTERISTICS

• TECHNOLOGY
• STRONG
• EFFECTIVE
• RELIABLE
• INNOVATORS
  
  Winner of the 2017 NMMA Innovation Award

The following features of the DF350A were key to receiving the award:

• The largest displacement among V6 engines, at 4.4 liters
• Suzuki Dual Prop System (for excellent traction and acceleration)
• Direct air intake and dual injector (to achieve high compression ratio and efficient combustion)
• Double air inlet louver system (for effective separation of air and water)
• Low fuel consumption
• Suzuki Dual Prop System
• The twin propeller system efficiently converts the 350 horsepower into underwater propulsion.

As an added bonus, because each propeller rotates in a different direction, excellent stability is achieved.

Double Air Intake Louvers System
The DF350A is equipped with a double louver on the air inlet to remove water from the air entering the cover.

The double louver removes water from the air. Incorporating a direct intake system, Suzuki's dual-rotation system contributes to higher engine performance.

Dual Fuel Injectors
Dual fuel injectors deliver the right amount of fuel at exactly the right time to the cylinder.

This dual injector contributes to higher performance and better fuel efficiency.

Shifted Central Axis
The offset center axis allows us to make our engines smaller, moving the center of gravity of the outboard forward while improving weight distribution, power output, balance and vibration reduction.

2-Stage Reduction Gears
The DF350A outboard also incorporates a 2-stage speed reduction, which results in a large gear ratio. It delivers strong torque for quick acceleration and excellent top speed.

Direct Air Intake
A new engine cover design provides the direct intake system with a smoother, cooler airflow that increases engine performance.

Lean Burn
Fuel efficiency matters whether you are at sea for pleasure or profit. Lean Burn Control Technology predicts fuel needs according to operating conditions and then delivers the optimum fuel/air mixture to the engine. The system is designed to save fuel both at low speeds and in the cruising range.

Suzuki Precision Control (Electronic Throttle and Gear Shift)
The sophisticated electronic drive system eliminates the friction and resistance of mechanical control cables. This gives smooth, precise control with immediate response, particularly at low revs and during manoeuvres. The system can be configured with single, double or triple installations and for double stations. Combined with the Lean Burn control system, it helps improve fuel efficiency across a wide range of modes

Variable Valve Timing (VVT)
Variable valve timing is used to metabolise intake timing with the camshaft to optimize timing for low to mid-range operation. This allows the engine to deliver maximum power output throughout its operating range, producing more low- to mid-range torque for strong acceleration. The whole process is done automatically leaving you to enjoy the power and performance.

Self-adjusting Timing Chain
The timing chain runs in oil so it never needs lubrication and has an automatic hydraulic tensioner so it stays properly adjusted at all times. Simple, effective and maintenance free.

Double Water Inlet
The engine cooling system relies on water supplied by the water inlet in the leg. Using this dual water intake configuration increases water flow to the foot, providing greater cooling performance. Placing the front inlet through the nose of the gearbox offers more water flow, especially at high speeds. The second inlet is also positioned below allowing the DF350A to operate in shallow water as well.

High Compression Ratio
(Highest compression ratio of SUZUKI outboards) The high compression ratio produces impressive performance and power from the 4390cc engine's expansion.

Oil filter
The location of the oil filter is easy for maintenance.

STANDARDS

MODEL DF350A
RECOMMENDED TRANSMISSION HEIGHT mm X:635, XX:762
STARTING SYSTEM Electric
WEIGHT kg *1 X: 330, XX: 339
ENGINE TYPE V6 - 55° DOHC 24-Valve
FUEL SUPPLY SYSTEM Electronic Fuel Injection
CYLINDERS 6
CUBIC cm3 4,390
DIAMETER × HEIGHT mm 98 x 97
MAXIMUM POWER kW 257.4
FULL POWER OPERATING RANGE rpm 5,700-6,300
STEERING SYSTEM Remote
OIL TANK CAPACITY Lit. 8.0
IGNITION SYSTEM Fully-transistorized
ALTERNATOR 12V 54A
ENGINE BASE Shear Mount
CONTROLS Power Trim and Tilt
GEAR RATIO 2.29:1
SPEEDS F-N-R (Drive-by-wire)
EXHAUST Through Prop Hub Exhaust
PROPELLER OPTIONS (Step)*2
All propellers are 3-blade type.
15"-31.5"

Dry weight: Calculates battery cable, excludes propeller and engine oil.
See your local dealer for propeller details.
The appearance, colors and equipment of outboards may vary depending on your supplier.

Specifications are subject to change without prior notice.

*Manufacturer information