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Suzuki DF90ATL Specifications
| Engine Model: Suzuki DF90ATL |
| Engine Type: 4-stroke inline 4-cylinder DOHC 16-valve gasoline outboard engine |
| Total Displacement: 91.6 cu.in (1.5 L) |
| Rated Engine Power: 90 Hp (66.2 kW) at 6000 rpm |
| Fuel System: Multi point sequential electronic fuel injection |
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| General Technical Data |
The Suzuki DF90ATL is a technologically
advanced 90 Hp outboard that redefines expectations in the mid-range
category. It is the lightest, most compact, and most fuel-efficient
outboard in its class, designed to deliver strong performance in a
lightweight package. Its most distinguishing feature is the large
reduction gear ratio of 2.59:1, which translates into powerful torque
for quick acceleration and the ability to turn large diameter propellers
with high propulsive efficiency.
The offset driveshaft design positions the powerhead closer to the
front, moving the outboard's center of gravity forward for improved
weight distribution, reduced vibration, more stable steering
performance, and a more compact overall footprint.
The Lean Burn Control System optimizes the air-fuel mixture based on
operating conditions, providing significant improvements in fuel economy
across all speed ranges, especially at cruising speed. With features
like the Suzuki Easy Start System, tilt limit protection, and the
optional Troll Mode System, the DF90ATL is engineered to provide a
premium and worry-free boating experience.
Engine Model: Suzuki DF90ATL
Engine Type: 4-Stroke, DOHC (Double Overhead Camshaft), 16-Valve,
In-Line 4 Cylinder
Number of Cylinders: 4
Valve Train Drive: Self-adjusting oil-bathed timing chain with automatic
hydraulic tensioner
Bore and Stroke: 75.0 mm x 85.0 mm (2.95 in x 3.35 in)
Piston Displacement: 1502 cc (91.6 cu. in)
Maximum Output: 66.2 kW (90 Hp)
Full Throttle Operating Range: 5300-6300 rpm
Idle Speed: 600-700 ± 50 rpm
Fuel Delivery System: Multi-Point Sequential Electronic Fuel Injection
Alternator: 12V 27A
Steering: Remote control
Trim Method: Power Trim and Tilt
Gear Ratio: 2.59:1 (2-stage gear reduction)
Gear Shift: F-N-R (Forward-Neutral-Reverse)
Exhaust: Through Prop Hub Exhaust
Propeller Selection: 13"-25" pitch range, various 3-blade aluminum
propellers available
Starting System: Electric
Ignition System: Full-transistorized ignition, Solid State Direct
Ignition
Engine Lubrication: Wet sump by trochoid pump
Engine Oil Capacity: 4.0-4.3 L (4.2-4.5 qt)
Gear Oil Capacity: 0.85 L (28.7/30.0 US/Imp. oz.)
Compression Ratio: 9.5:1
Spark Plug: NGK DCPR6E
Spark Plug Gap: Standard: 0.8-0.9 mm (0.031-0.035 in)
Valve Clearance (Intake): 0.23-0.27 mm (0.009-0.011 in) (cold)
Valve Clearance (Exhaust): 0.30-0.34 mm (0.012-0.013 in) (cold)
Fuel Type: Alcohol-free unleaded gasoline
Minimum Fuel Octane Rating: 87 (R+M/2 method) or 91 (Research method)
| Powerhead |
The DF90ATL is built upon a robust inline four-cylinder block with a
displacement of 1502 cc, utilizing a bore and stroke of 75.0 mm and 85.0
mm respectively. The powerhead features a DOHC 16-valve configuration
for optimal airflow and combustion efficiency, with four valves per
cylinder.
A key feature is the self-adjusting oil-bathed timing chain, which runs
in an oil bath so it never needs lubrication and is equipped with an
automatic hydraulic tensioner that keeps it properly adjusted at all
times. This design offers higher durability compared to belt systems and
is completely maintenance-free.
The offset driveshaft positions the crankshaft in front of the
driveshaft, moving the outboard's center of gravity forward. This
results in reduced vibration, a more compact engine footprint, more
stable steering performance, and keeps the overall motor's weight closer
to the boat transom and therefore closer to the boat's center of
gravity.
Cylinder bore std: 75.000-75.020 mm (2.9598-2.9535 in)
Piston skirt diameter std: 74.970-74.990 mm (2.9516-2.9524 in)
Piston to cylinder clearance std: 0.020-0.040 mm (0.0008-0.0016 in)
Piston ring end gap std: 0.30-0.45 mm (0.0118-0.0177 in)
Valve diameter (Intake): 27.5 mm (1.08 in)
Valve diameter (Exhaust): 22.9 mm (0.90 in)
| Fuel System |
The DF90ATL's fuel system is centered around the Suzuki Lean Burn
Control System, an intelligent technology that supplies the right fuel
and air mixture depending on navigation conditions. By predicting fuel
needs based on operating conditions and delivering an optimized air-fuel
mixture, this system provides significant improvements in fuel economy
across all speed ranges, especially at cruising speed, reducing fuel
costs and enhancing efficiency.
The Multi-Point Sequential Electronic Fuel Injection system precisely
meters fuel to each cylinder for optimal combustion, ensuring crisp
throttle response, smooth acceleration, and reduced emissions. The ECU
monitors throttle setting, engine RPM, cylinder wall temperature,
air-intake temperature, and atmospheric pressure simultaneously to
determine the most optimal injection timing. The Suzuki Easy Start
System allows the operator to simply turn and release the key, with the
starter remaining engaged until the engine starts.
An optional Troll Mode System is available for precise low-speed control in trolling applications, allowing engine speed adjustments in 50 rpm increments from idle up to 1200 rpm. The Water Detecting System alerts the operator with both visual and audio warnings if water is present in the fuel, preventing issues like poor combustion, power loss, and corrosion.
| Lubrication System |
The DF90ATL employs a wet sump lubrication system with a trochoid pump to ensure consistent pressurized oil delivery to all critical engine components. The engine has an oil capacity of 4.0 to 4.3 liters with filter change.
Recommended engine oil is high-quality 4-stroke motor oil meeting NMMA FC-W certification or API classification SG, SH, SJ, SL, SM, with viscosity SAE 10W-40 recommended for most conditions. The engine does not come pre-filled with oil; the correct type and amount must be added before the first use.
| Cooling System |
Engine temperature is managed by a reliable direct water-cooled system. A water pump, located in the lower unit, draws water from the surrounding environment and circulates it through water jackets in the cylinder block and powerhead.
For post-operation maintenance, the DF90ATL is equipped with dual engine flush ports that make flushing the cooling system much easier, allowing a garden hose to rinse salt, sand, and other debris from the cooling passages, protecting the engine from corrosion. The thermostat should be inspected periodically according to the maintenance schedule.
| Mid Section and Lower Unit |
The mid-section houses the offset driveshaft, contributing to the forward center of gravity and overall compactness. The lower unit features a robust gearcase with a 2.59:1 gear ratio, the largest in its class, achieved through a 2-stage gear reduction system.
This system, enabled by the offset driveshaft, provides a first stage
reduction between the crankshaft and driveshaft and a second stage
reduction inside the gear case. The higher gear ratio allows the engine
to turn larger diameter propellers with tremendous power, resulting in
quick acceleration, high propulsive efficiency, and the ability to
maintain propeller rotation even with a larger load.
The lower gear case utilizes a streamlined hydrodynamic design that
reduces drag as the lower unit moves through the water by up to 36%
compared to traditional designs, contributing to faster acceleration and
increased speed. Drive line impact protection is provided by a spline
drive rubber hub. Exhaust gases are channeled through the propeller hub
for quieter operation.
| Trim and Tilt System |
The Power Trim and Tilt (PTT) system provides hydraulic control over the
outboard's angle, allowing the operator to adjust boat trim for optimal
performance, fuel efficiency, and ride comfort. The trim angle range is
0-20 degrees (-6 to 14 degrees), and the maximum tilt angle is 75
degrees (-6 to 69 degrees). The system is operated by a rocker-type
switch protected by a rubber thumb pad on top of the remote control box
handle.
The Tilt Limit System incorporates a user-adjustable, step-free
continuous tilt limit switch that prevents the outboard from tilting
beyond a predetermined point, protecting both the engine and the boat
from damage caused by excessive tilting and allowing installation on
almost any boat. A manual release valve is provided for emergency
operation.
| Propeller Information |
The DF90ATL is designed to work with a comprehensive range of propellers
to match various boat types and load conditions. The recommended
propeller pitch selection ranges from 13 inches to 25 inches, with a
standard propeller of 3 x 13 3/4 x 19 inches. All propellers are
three-blade aluminum type.
Available propeller options include various diameters and pitches: 14 x
13, 13-7/8 x 15, 13-3/4 x 17, 13-3/4 x 19, 13-3/4 x 21, 13-3/4 x 23,
13-1/2 x 15, 14 x 17, 14 x 19, 14 x 21, 14 x 23. The propeller nut must
be torqued to specification and secured with a new cotter pin each time.
Installing a propeller with pitch either too high or too low will cause
incorrect maximum engine speed, which may result in severe damage to the
motor.
| Dimensions and Weight |
Transom Height (Long Shaft - L): 508 mm (20 in)
Overall Length (front to back): 725 mm (28.5 in)
Overall Width (side to side): 460 mm (18.1 in)
Overall Height (Long Shaft): 1480 mm (58.2 in)
Dry Weight (Long Shaft): 155-157 kg (341-346 lbs)
Engine Mounting: Shear mount
| Maintenance Data |
Initial Service: Perform at 20 hours or 1 month
Engine Oil: Replace every 100 hours or 12 months
Engine Oil Filter: Replace at initial 20 hours, then every 200 hours or
12 months
Gear Oil: Replace every 100 hours or 12 months
Spark Plugs: Inspect every 100 hours or 12 months
Valve Clearance: Inspect every 300 hours or 36 months
Water Pump Impeller: Inspect every 200 hours; replace as needed
Low Pressure Fuel Filter: Inspect every 100 hours; replace every 2-3
years
Anodes (External): Inspect every 100 hours or 12 months
Propeller Nut and Cotter Pin: Inspect at each interval
Bolts and Nuts: Check tightness at each interval
Engine Oil Capacity: 4.0 L (4.2 qt) without filter; 4.3 L (4.5 qt) with
filter change
Recommended Oil: 4-stroke motor oil, NMMA FC-W oil, or API SG, SH, SJ,
SL, SM
Oil Viscosity SAE 10W-40
Gear Oil Capacity: 0.85 L (28.7/30.0 US/Imp. oz.)
Recommended Oil: Suzuki Outboard Motor Gear Oil or API GL5, SAE 90
Hypoid gear oil
Standard Spark Plug: NGK DCPR6E (resistor type only)
Spark Plug Gap: 0.8-0.9 mm (0.031-0.035 in)
| Tightening Torques |
Cylinder head cover bolt: 11 Nm (8.0 lb-ft)
Cylinder head bolt (8 mm): 23 Nm (16.6 lb-ft)
Cylinder head bolt (10 mm): 70 Nm (51.0 lb-ft)
Crankcase bolt (Outside): 25 Nm (18.0 lb-ft)
Crankcase bolt (Inside): 52 Nm (37.5 lb-ft)
Conrod cap bolt: 47 Nm (40.0 lb-ft)
Camshaft housing bolt: 11 Nm (8.0 lb-ft)
Oil pump bolt: 15 Nm (11.0 lb-ft)
Chain tensioner adjuster bolt: 11 Nm (8.0 lb-ft)
Timing chain guide bolt: 23 Nm (16.6 lb-ft)
Intake manifold bolt / nut: 23 Nm (16.5 lb-ft)
Fuel delivery pipe bolt: 23 Nm (16.5 lb-ft)
Low pressure fuel pump bolt: 10 Nm (7.0 lb-ft)
Flywheel bolt: 196 Nm (142.0 lb-ft)
Starter motor mounting bolt: 23 Nm (16.6 lb-ft)
Oil pressure switch: 13 Nm (9.5 lb-ft)
Thermostat cover bolt: 10 Nm (7.0 lb-ft)
Water pump case bolt: 17 Nm (12.3 lb-ft)
Power unit mounting bolt (8 mm): 23 Nm (16.5 lb-ft)
Power unit mounting bolt (10 mm): 50 Nm (36.0 lb-ft)
Driveshaft housing bolt: 50 Nm (36.0 lb-ft)
Lower mount bolt: 60 Nm (43.4 lb-ft)
Propeller shaft bearing housing bolt: 23 Nm (16.6 lb-ft)
Propeller nut: 55 Nm (40.0 lb-ft)
Engine oil filter: 14 Nm (10.0 lb-ft)
Engine oil drain plug: 13 Nm (9.5 lb-ft)
| Boat Applications |
Fishing Boats: An excellent primary power source for small to mid-sized
fishing boats, bay boats, and side consoles, offering the torque needed
for quick planing and efficient trolling with the optional Troll Mode
System. The 2026 Alumacraft Classic 165 Sport is powered by a Suzuki
DF90ATL, demonstrating its suitability for freshwater fishing
applications. Rigid Inflatable Boats (RIBs): Suitable for RIBs and small
center consoles where lightweight power is advantageous.
Commercial and Work Applications: Its robust construction, fuel
efficiency, and reliability make it a dependable choice for various
light-duty commercial applications. Saltwater Use: Extensively protected
by the Suzuki Anti-Corrosion System, with a special anticorrosion
treatment that helps protect its parts from corrosive agents like sea
salt, increasing the outboard's durability. Features like dual engine
flush ports and a water-detecting fuel system make it exceptionally
well-suited for long-term durability in harsh saltwater environments.
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