PRODUCT INFORMATION

FOUR-STROKE / Electronic Fuel Injection

Suzuki’s Award Winning Technology

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DF250

The product of unrivaled expertise and world classtechnology, Suzuki’s four-stroke outboards havelong been on the cutting edge of outboardperformance winning acclaim and awards fortheir advanced technology, innovative ideas,and designs. We were the first to introduce adigital Electronic Fuel Injection four-stroke;an idea that allowed the DF60 and DF70 toreceive further recognition from theInternational Marine Trades Exposition andConvention when they captured the IMTECInnovation Award. We were the first to offer anautomotive type self-adjusting timing chain ina four-stroke engine with performance-enhancing dual overhead cams and four valvesper cylinder. This brought us recognition again,when our DF40 and DF50 received the IMTECInnovation Award making Suzuki the firstmanufacturer to receive this distinguished awardtwo years in a row, and also giving us our thirdIMTEC award, again an industry first. DF90/115and DF140 are the first to offer an offsetdriveshaft with a two-stage cam drive system andtwo-stage gear reduction system, making them themost compact outboards in their class.

At its first showing at a special previewat the 2003 Miami InternationalBoat Show, the DF250 captured theNMMA (National MarineManufacturers Association) 2003Innovation Award making this thefourth Innovation Award for Suzuki.

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The flagship DF250 is the industry’s first250PS (184kW) V6 four-stroke outboard and themost powerful outboard ever built by Suzuki. Its3614cm3 (220.5 cu. in.) displacement is ofcourse, our largest to date, and the largest todate in the industry as well. At 69PS (51kW) perliter, it holds the greatest power to displacementratio the industry has ever seen in the four-stroke category. Additionally it holds the indus-try’s greatest power to weight ratio and is thelightest outboard motor in this category.

■ "The Ultimate" DF250Relying on experience we’ve gained through themanufacture of not only outboards, but techno-logically-advanced motorcycles and automo-biles, our engineers have put decades of knowl-edge into the design, development, and produc-tion of an all new V6 motor designed specificallyfor outboard use. This new V6 holds some of ourmost advanced innovative ideas to date, makingit a showcase for Suzuki’s advanced four-strokeoutboard technology.

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■ The Ultimate in Performance

Cam Position Sensor

Rotation DirectionVVT Actuator

Throttle Opening Angle

Water Temp

Feed back

Cam Position

Crank Position

Manifold Pressure

Water Temp Sensor

Throttle Sensor

Map Sensor*

Intk Cam Shaft Ex Cam Shaft

Crank Position Sensor

Duty Control

Crank Shaft

ECM

TargetAdvance

Actual Valve Timing

Intk Cam Shaft

Retard

Advance

Drain

OilFilter

OilPump

Oil Pan

Engine Oil Pressure

Oil Control Valve (OCV)

Signal*Manifold Absolute Pressure Sensor

TOR

QU

E (

50N

• m)

LOW MID

ENGINE SPEED (rpm)

HIGH

with VVT

without VVT

Diagram of VVT Mechanism

Torque CurveDOHC 24-Valve with VVT DeliversHigh Performance

Our engineers designed a 3.6-liter V6 engine—thelargest displacement found in the industry thus far—and anaggressive cam profile designed specifically for the DF250to create the industry’s first 250PS (184kW) four-strokeoutboard. However, our goal was not just to create anoutboard that could deliver 250PS (184kW), but to createan outboard that could deliver high performance that suitsits 250PS (184kW) output along with the many benefitsthat a four-stroke can deliver.

A high performance camshaft designed to deliver250PS (184kW) produced the wanted power output, but toget the strong mid and low-end torque outboards needwhen accelerating requires altering valve timing. Ingeneral, only using a camshaft setting like those found inracing engines produces an engine that develops insuffi-cient low and mid range torque. This is because the valvetiming for intake and exhaust differs according to load andengine speed.

* At the comparison test, Multi-Stage Induction System ofthe motor was operated.

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The common idea is that the intake valve opens after theexhaust valve is fully closed however, the intake valveactually starts opening before the exhaust valve fullycloses, creating a momentary overlap in the timing whereboth valves are open. Using VVT (Variable Valve Timing)in the DF250, this overlap can be increased or decreasedby altering intake timing with the camshaft, therebyoptimizing camshaft timing for low range and mid rangeoperation. As the DF250’s camshaft is already setup todeliver maximum output at high rpm, a change in timing inthis range is mostly unnecessary. Increasing the overlap isnecessary during acceleration in the low and mid powerrange, but no change in timing is required for stable idling.In the DF250’s VVT system there are two chambers withinthe VVT actuator, one on the phase angle forward side andanother on the phase angle backward side, to whichhydraulic pressure is continuously applied to change thevalve timing of the intake cam. When the engine isstopped, idling or other times that there is no oil pressurein the system, the VVT actuator locks, disengaging thesystem.

Graph Illustrating the Variance in Valve LiftUsing VVT

Cylinder Block Cylinder Head

Camshaft

Valve Overlap

Val

ve L

ift Ex Valve

Advance40° Movable Angle

Intk Valve

Retard

Crank Angle

Intake

VVT

Exhaust

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Multi-Stage InductionMulti-stage induction enhances engine performance by

changing the length of intake manifold pipes according toengine speed. The system utilizes two intake manifoldpipes per cylinder, one operating at low engine speed andanother operating at high. When the engine is operating atlower rpm, air enters the combustion chamber through the

Air Flow in Multi-Stage Induction Module

Lower rpm High rpm

Multi-Stage Induction Module

Close Open

TOR

QU

E (

50N

• m)

LOW MID

ENGINE SPEED (rpm)

HIGH

without Multi-Stage Induction

with Multi-Stage Induction

Torque Curve

longer, curved manifold pipe. The length of the pipe isdesigned for entering the most suitable volume of fresh airinto the chamber to improve combustion and boost low-end torque.

As rpm pass a preset threshold, the valve on the directintake pipe opens up letting air enter directly into thecombustion chamber. Short, straight and lacking resistanceit gets a greater volume of air into the chamber, increasingthe engine’s ability to breathe at high rpm, thus improvinghigh speed power output.

The engine cover is designed with a large air intake,which extends from the back of the cover, well aroundboth sides to provide maximum airflow into the cowling.

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Two-Stage Gear ReductionWith such a high performance engine now at our

disposal, losing any power in the propulsion system wouldbe a waste, so our engineers chose an efficient means ofsupplying maximum propulsion. A propeller rotating athigh speed in the water has a tendency to slip and whentwo propellers of the same pitch but different diametersare rotated, the smaller propeller will slip more than thelarger. So to obtain maximum propulsion, spinning a largerdiameter propeller with a suitable pitch is the answer.

But to spin a larger propeller, more torque in thepropeller shaft becomes necessary. In order to obtain therequired amount of torque however, the correspondingincreases in weight and resistance due to the use of largergears and a larger gearbox do not always provide effectiveresults. The answer to this dilemma is found in the use of atwo-stage gear reduction system that provides the neces-sary torque without adding unwanted bulk and weight.

The DF250 utilizes a first stage gear reduction (32:40)between the crankshaft and driveshaft, and a second stagereduction (12:22) in the lower unit’s gear case, resulting inan overall gear ratio of 2.29. This is the largest gearreduction ratio found in any outboard over 200PS (147kW)two-strokes included. Such a powerful reduction allows

the DF250 to turn a 16-inch diameter propeller, which,while being larger than the 14-1/2-inch diameter propellerfound on the two-stroke DT225, is also larger than thosepreviously used on a V6 outboards. The propeller used onthe DF250 is specially designed for greater accelerationand maximum speed.Along with greater acceleration, the gear reduction incombination with the four-stroke engine’s wide powerband is capable of handling a wide variety of loads, whichis a significant benefit to boaters whose loads vary fromday to day.

DT225 DF250

Propeller Diameter Comparison

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55-Degree Bank Angle Creates aCompact V6

With the DF250, one major design objective ourengineers set out to realize was to design and produce acompact, narrow profile motor. This was met by abandon-ing the 60-degree bank angle normally utilized in V-typeblocks and designing an all-new V-design block using a55-degree bank angle—an industry first. When comparedto the industry norm of 60-degrees, as shown in the enginecover comparison, the difference in size is quite clear.

■ Compact DesignsEngine Cover Profile Comparison

Offset Drive Shaft

Offset DriveshaftSuzuki’s utilization of an offset driveshaft in the DF90,

115 and 140 has proven successful in reducing the size ofthe outboard. The DF 250 benefits from this same designwhich positions the crankshaft in front of the drive shaft,simultaneously moving the outboard’s center of gravityforward. This system adds to the compactness of theoutboard and provides an improvement in power perform-ance. It also places the engine’s axis of inertia, the pointwhere vibrations produced by the engine are at a mini-mum, up over the upper engine mount thus greatly reduc-ing vibration. 12:22=1.83

Brand A V6Four-Stroke

DF250

Cylinder Block

55° 32:40=1.25

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Two-Stage Cam Drive SystemThe two-stage cam drive system utilized in the DF250 incor-

porates both gears and a chain. The system’s first stage gearstransfer power between the crankshaft and the drive shaft (32:40)while the second stage utilizes a chain to deliver power from thedrive shaft to the camshaft (20:32). This allows for the use ofsmaller diameter cam sprockets, which in turn allows for areduction in valve angles also reducing the size of the cylinderhead. The timing chain is equipped with an automatic hydraulictensioner to keep the chain properly tensioned. This systemprovides years of maintenance-free operation.

Direct IgnitionThe DF250’s V6 engine utilizes an advanced direct ignition

system, which uses integral type spark plug caps with ignitioncoils. While reducing the number of parts and simplifying thewiring system, this arrangement also greatly reduces electronicengine “noise” that can interfere with VHF radios, fish findersand other marine electronics. Controlled by the outboard’s power-ful 32-bit computer this system provides each cylinder withoptimum spark strength and timing.

■ Durability and ReliabilityKeeping The Engine and Components Cool

Fitted with fan blades the flywheel serves a dual purpose byefficiently expelling heat from within the engine cover out of theside of the cowl, keeping the temperature within the cowl undercontrol.

Water circulating around the oil jacket located at the base ofthe V-bank cools oil flowing through the pipe, keeping oil tem-perature under control. This contributes to the cooling of theengine thereby enhancing durability.

The DF250 also utilizes piston cooling jets, each of whichshoots a stream of oil onto the backside of the pistons to aid incooling. Fine nozzles deliver a well-defined stream of oil that isprecise and accurate. The engine is equipped with another coolingjet that shoots a stream of oil onto the main cam chain and drivegear to keep those components cool and lubricated as well.

Suzuki Anti-Corrosion FinishSuzuki has formulated a new anti-corrosion finish that both

increases the durability of the engine and protects those parts ofthe aluminum exterior that are constantly exposed to saltwater.The Suzuki Anti-Corrosion Finish is an specially formulatedadvanced finish that offers maximum bonding of the finish to thealuminum surface for an effective treatment against corrosion.The Suzuki Anti-Corrosion Finish can be found on all 2004 four-stroke models from the DF25 and up.

Piston Cooling Jet

Flywheel Magneto

Cam Drive System20:32=1.60

32:40=1.25

Plug Top Ignition Coil

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■ Excellent Fuel Economy

Multi Point Sequential Electronic Fuel Injection

The graph shows acomparison in theperformance of theDF250 engine with thetwo-stroke direct fuelinjection (D/I) model.At idle, fuel consump-tion of the DF250 isover 60% less than theDI model. Even whenoperation at maximumperformance level, theDF250 consumes lessfuel than its two-strokecounterpart.

Multi Point Electronic Fuel InjectionAs Suzuki was the first in the industry to incorporate

multi point electronic fuel injection in a four-stroke out-board with the DF60 and DF70, it is only natural that theDF250 would incorporate the same. Along with Suzuki’sMulti Point Sequential Fuel Injection, the DF250 incorpo-rates an ECM (Engine Control Module) which constantlymonitors crucial data, in real time, froma series of sensors placed in criticalareas on the engine. This comprehen-sive network of sensors includes theManifold Absolute Pressure Sensor,Crankshaft Position Sensor, Intake AirTemperature Sensor, Cylinder WallTemperature Sensor, Camshaft PositionSensor and Exhaust Jacket TemperatureSensor. To process all of this data

FlywheelMagneto

High PressureFuel Filter

Fuel CoolerPressure Regulator

Evaporation Hose

Vapor Separator

High Pressure Fuel Pump

Float

Squeeze Pump

Low Pressure Fuel Filter

Low Pressure Fuel Pump

Purge Control Valve

Battery

Shift Position Sensor

Fuel Tank

OFF

IG

ST

E.C.M.

Starter Relay

Main Relay

IgnitionSwitch

Fuse

Neutral Switch

Manifold Absolute Pressure Sensor (MAP Sensor)

Intake Manifold

Injector

Throttle Body

Silencer

Idle Air Control Valve (IAC Valve)

Vacuum Switching Valve (VSV)

Pilot AirAdjust Screw

Throttle Position Sensor

Intake Air Temp Sensor (IAT Sensor)

Cylinder Head

Ignition Coil

Cylinder Block

Oxygen Sensor (Service tool only)

Cylinder Wall Temp Sensor

Spark Plug Exhaust JacketTemp Sensor

Camshaft Position Sensor (CMP Sensor)

Oil Control Valve (OCV)

Crankshaft Position Sensor (CKP Sensor)

Comparison

IDLE

5

10

15

20

0MID

RPM

FU

EL

CO

NS

UM

PT

ION

(G

PH

)

WOT

Brand A (2st D/I 250PS)

DF250

■ Low Emissions

Injector & Manifold Module

*According to Suzuki Internal Running Test

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Alternator Output

0

5

10

15

20

25

30

35

40

45

50

55

1000 2000 3000 4000 5000 (rpm)

(A)

efficiently, the ECM relies on a very powerful 32-bitcomputer which instantly calculates the optimum amountof fuel to be injected at high pressure into each of thecylinders by the Multi Point Sequential Fuel Injectionsystem. This system greatly reduces exhaust emissionsallowing the DF250 to pass both the EPA 2006 regulationsand CARB 2008 regulations, the strictest exhaust regula-tions to date, while providing lower fuel consumption,smooth starts, crisp acceleration, smooth performance andmaximum efficiency.

CARB 3 StarsThe DF250 has received the CARB three-star rating

which identifies engines that meet the California AirResources Board’s 2008 exhaust emission standards. Thestrictest exhaust regulations to date, they represent a 65%reduction in emissions from the EPA 2006 emissionstandards.

■ Convenient Function

High Output AlternatorThe outboard is also equipped with a high output

alternator that delivers 54 A (12V) of electrical power.Designed to produce a majority of this power at low rpm,around 38 A is delivered even at 1,000rpm. It delivers agenerous amount of current to keep an assortment ofelectronics up and running.

Tilt Limit SwitchThe motor tilt system

incorporates a user settabletilt limit switch, whichprevents the motor fromtilting beyond a predeter-mined position. This can beused to protect both theboat and motor fromdamage that can occurwhen tilting the motor.

Other Features● Counter rotation models, the DF250Z, are available in

25-inch and 30-inch transom lengths for greater compat-ibility with a wider range of offshore boats.

● Lower cover separates into two sections to allow easieraccess for maintenance to the V6 engine.

● An oil change reminder system, built into the Multi-Function Tachometer (Optional), informs the user with aflashing oil lamp when it is time to change the oil.

● Oil changes are easy with the oil drain plug located onthe front of the oil pan, the oil filler cap on the top of thecylinder head, and a spin-on oil filter.

● A comprehensive monitoring system built into the Multi-Function Tachometer (Optional) detects abnormalities inthe running of the outboard to provide information andalerts so that appropriate measures can be taken beforethe problem becomes serious.

Tilt Limit System

Fuel Filter

Fuel FilterThe fuel system is equipped with

a large and easy to maintain fuelfilter which removes contaminantsfrom the fuel before they reach theengine to protect the engine fromdamage.

DF250 FEATURESMODEL DF250 DF250Z (Counter Rotation)

ENGINE TYPE Four-Stroke DOHC 24 Valves

FUEL DELIVERY SYSTEM Multi Point Sequential Electronic Fuel Injection

TRANSOM HEIGHT mm (in.) X: 635(25), XX: 762(30)

STARTING SYSTEM Electric

WEIGHT kg (Ibs.) X: 263 (580)XX: 268 (591)

NO. OF CYLINDERS V6 (55-degree)

PISTON DISPLACEMENT 3,614 (220.5)cm3 (cu. in.)

BORE × STROKE m/m (in.) 95 × 85 (3.74 × 3.35)

MAXIMUM OUTPUT 250 (184)/5800PS (kW) /rpm

FULL THROTTLE 5500-6100OPERATING RANGE rpm

STEERING Remote

OIL PAN CAPACITY l 8.0 (7.6/9.1)(US/Imp. qt.)

IGNITION SYSTEM Fully-transistorized

ALTERNATOR 12V 54A/3000rpm

ENGINE MOUNTING Shear Mount

TRIM METHOD Power Trim and Tilt

GEAR RATIO 2.29 : 1 (Two-stage Reduction Gear)

GEAR SHIFT F-N-R

EXHAUST Through Prop Hub Exhaust

DRIVE PROTECTION Rubber Hub

PROPELLER SIZE (in.) 16 × 17 16 × 18.5OPTIONAL 16 × 18.5 16 × 20

16 × 20 16 × 21.516 × 21.5 16 × 2316 × 2316 × 24.5

DF250 SPECIFICATIONS● V-design Engine Block using a 55-degree

Bank Angle● DOHC 24-valve Engine with Variable

Valve Timing System● Multi-Stage Induction● Multi Point Sequential Electronic Fuel

Injection● Direct Ignition● Offset Driveshaft● Two-stage Gear Reduction● Two-stage Camshaft Drive System● Flywheel Designed with Fan Blades● 54A Alternator● Counter Rotation Models Available● Tilt Limit Switch● Oil Change Reminder System● Low Oil Pressure Caution● Over-Rev Limiter● Overheat Cooling Water Caution● Self Diagnostic System● Neutral rpm Limiter● Anti-Corrosion Protection● Freshwater Engine Flush Port● High Performance 16-in. Diameter

Stainless Steel Propeller (Optional)● Multi Function Tachometer (Optional)

CARB Three-Star LabelThe three-star label identifiesengines that meet theCalifornia Air ResourcesBoard’s 2008 exhaustemission standards. Enginesmeeting these standards have65% lower emissions thanEPA 2006 exhaust emissionstandards.

EPA 2006 LabelSuzuki’s four-stroketechnology ensurecompliance with EPA2006 exhaust emissionstandards set by theU.S. EnvironmentalProtection Agency.

* Boats and motors come in a large variety of combinations. See your authorized dealer for correct prop. selection to meetrecommended RPM range at W.O.T.

Please read your owners manual carefully. Remember, boating and alcohol or other drugs don’t mix. Please operate youroutboard safely and responsibly.

Suzuki encourages you to operate your boat safely and with respect for the marine environment.

SUZUKI MOTOR CORPORATION reserves the right to change, without notice, equipment, specifications, colors, materialsand other items to apply to local conditions. Each model may be discontinued without notice. Please inquire at your local dealerfor details of any such changes.Actual body colors may differ slightly from the colors in this brochure.

http://www.suzuki.com

DF250 Product Information (ASMC) 030599999-C2045-101 Printed in Japan

* The weight of the motors are “Dry-Weight”, not including propeller.