Suzuki DF175AP White

Semi-Direct Air Intake System

A specially designed cowl and semi-direct air intake system were designed to provide cooler air to the tuned long-track intake manifold while a four valve per cylinder DOHC powerhead with Variable Valve Timing lets the engine breathe more efficiently increasing acceleration and top end speed. Added to that are a fuel injection system and Suzuki’s Lean Burn Technology for improved fuel economy.

Big Block High Performance Engine

The new DF175AP/150AP development team based both of these new Suzuki outboards on a big block inline four-cylinder four-stroke engine with a 2,867cm3 displacement. The block is topped with a DOHC powerhead that provides four-valves per cylinder for high performance. While the large displacement allows both to deliver exceptional acceleration and velocity, our engineers made sure that the outboard’s final dimensions are as compact and lightweight as possible. Both outboards feature some of the best of Suzuki’s advanced technologies that have been developed to extend engine performance.

High 10.2:1 Compression Ratio

Compression and displacement each play important roles in delivering performance and power output. Displacement has a direct effect on acceleration and torque so a bigger displacement is generally going to deliver more of both. Higher compression ratios allow the engine to get more output out of the combustion process resulting in noticeable improvements in performance and power. Drawing on our extensive motorsports experience and expertise in building race engines, Suzuki engineers have combined a 2,867cm3 displacement (the largest in each outboard’s class) with a high compression ratio of 10.2:1 to obtain great performance from these compact engines

Resonator

The engine’s exhaust system is a well-known source of engine noise, but another, often overlooked source is the intake manifold. Air being sucked into the intake manifold at high velocities can generate a harsh sound. The DF175AP/DF150AP incorporate an air intake resonator that reduces such noise keeping operation exceptionally quiet.

Suzuki Precision Control ( Electronic Throttle and Shift System)

Suzuki Precision Control is a technologically advanced computer-based control system that replaces the mechanical control cables found in conventional control systems with electronic wiring that eliminates the source of friction and resistance. While you enjoy smooth throttle and shift operation with minimal friction, the system’s computer is processing and transmitting commands in real-time to actuators at the engine that deliver precise throttle control with smoother, decisive shifting. This is most evident in the low rpm range where operation is noticeably smooth and accurate. When combined with Suzuki’s Lean Burn Control System it allows control of fuel and air flow to boost the limit of the controllable revolution range improving fuel economy over a wide operating range. Suzuki Precision Control also features built-in systems that help guard the engine and drive against damage due to mishandling, and its design and simple wiring make installation easy, reducing the time required for rigging and adjustment.
The system offers precision control for single, twin, triple or quad installations as well as dual station operation.

Suzuki Lean Burn Control

The Suzuki Lean Burn Control System is an intelligent fuel delivery system that achieves remarkable improvements in fuel consumption making fuel-efficient four-stroke outboards even more economical. Monitoring engine performance and operating conditions in real time, the system uses the 32-bit onboard ECM to predict fuel needs and deliver a leaner, more precise fuel mixture across the outboard’s operating range. The results show significant improvements in fuel economy across the entire powerband, including the cruising range where the engine is used a majority of the time.

Counter Balancer System

ne of the inherent characteristics common to in-line four-cylinder engines when operating at high rpm is a secondary vibration that is directionally in line with the piston’s movements. To neutralize this vibration, Suzuki engineers utilize a secondary balancer system that counters the piston’s movement with a horizontal motion. To achieve this, the balancer is divided into left and right sections each rotating in an opposite direction at twice the speed of the crankshaft, effectively countering the secondary vibrations and producing smoother engine operation.

O2 Sensor Feedback Control System

A key sensor in the electronic fuel injection system, the O2 Sensor Feedback Control system provides accurate, real-time information that the ECU uses to manage the fuel/air ratio as operating conditions change. Utilized on many of Suzuki’s high-end outboards, the O2 Sensor Feedback Control system helps maintain optimum engine operating efficiency across the engine’s full operating range.

Suzuki Selective Rotation

Large boats equipped with multi-outboard installations generally pair a standard rotation outboard with a counter-rotation model to keep the boat traveling in a straight line and on an even keel. Once requiring the purchase of a dedicated counter-rotation model, Suzuki’s innovative Suzuki Selective Rotation eliminates that need by incorporating a special, unified design of gears, shaft, and bearings in the lower unit that allow the outboard to operate reliably and efficiently in either direction. Available on both the DF175AP and DF150AP, counter-rotation operation requires an optional activation switch that connects to a circuit inside of the engine compartment plus the installation of a counter-rotation propeller

Offset Drive Shaft

Pioneered by Suzuki, the use of the offset drive shaft on four-stroke outboards has long been utilized to reduce the size of the outboard. Found on all Suzuki four-strokes from the DF70A and up, this design positions the crankshaft in front of the drive shaft simultaneously moving the outboard’s center of gravity forward. While the design contributes greatly to the outboard’s overall compactness and increased power performance, it also moves the engine’s axis of inertia, the point where engine vibrations are at a minimum, up over the upper engine mount, thus greatly reducing vibration. These outboards also incorporate two-stage gear reduction designed to take maximum advantage of the power produced by these high performance engines. Providing a final drive ratio of 2.50:1—the largest you can find in either of these outboard classes—it delivers powerful torque for quick acceleration and great top-end speed.

Multi Stage Induction ( MSI)

Getting the right amount of air into the cylinder has a great impact on performance. High-speed operation typically requires a greater volume of air, low-speed less. Suzuki’s Multi-Stage Induction system meets these needs by utilizing two intake manifold pipes per cylinder to ensure the engine gets the right amount of air. At low rpm, air enters the combustion chamber through a longer, curved manifold pipe designed to improve combustion and boost low-end torque. As rpm increases, the valves open on the direct intake pipes. Shorter and lacking resistance, these pipes allow a greater volume of air into the chamber, increasing the engine’s ability to breathe efficiently at high rpm resulting in higher power output during high-speed operation.

Fuel Consumption Comparison

Performance Curve Comparisom

Accelleration Time Comparison

Tilt Limit System

To protect the boat and motor from damage that can occur when tilting the motor, both outboards incorporate a user adjustable tilt limit switch that prevents the outboard from tilting beyond a predetermined point.

Dual Engine Flush Ports

Over time, salt, sand, and dirt buildup can restrict flow in the cooling system causing damage. To help prevent such buildup, both outboards are equipped with two freshwater flush ports that make flushing the cooling system as easy as possible. With one port located on the port side of the down housing and a second on the front panel, you’ll always have easy access to the flushing system whether the boat is in or out of the water.