1988 Evinrude 90 HP Outboard Manual

The 1988 Evinrude 90 HP Outboard is a powerful marine engine featuring V4 configuration, loop-charged induction system, 89.7 cubic inch displacement, thermostatically controlled cooling, CD ignition system, built-in fuel pump, 12-volt electric starting, power trim and tilt, and corrosion-resistant materials. Below are key sections for safety, specifications, operation, maintenance, troubleshooting, and repair procedures.

1. Features at a Glance 2. Installation 3. Operation Procedures 4. Specifications 5. Controls and Instrumentation 6. Fuel System 7. Electrical System 8. Cooling System 9. Maintenance Schedule 10. Storage Procedures 11. Troubleshooting

Features at a Glance

Key components: V4 powerhead, CD ignition system, thermostatic cooling, power trim/tilt, corrosion-proof mounting hardware, remote control box, and instrumentation.

Feature	Description
Powerhead	90° V4 configuration, 89.7 cu in displacement
Ignition System	Capacitor Discharge with electronic timing
Fuel System	Dual carburetors with built-in fuel pump
Cooling System	Thermostatically controlled water pump
Starting System	12-volt electric start with alternator
Trim/Tilt System	Power trim and tilt with manual release
Gearcase	Shear-proof prop hub, 2.00:1 gear ratio
Exhaust System	Through-propeller exhaust
Mounting System	Corrosion-resistant hardware
Control System	Remote control box with safety lanyard

Installation

Proper installation ensures optimal performance and safety.

Select appropriate transom: Ensure transom can support engine weight and horsepower.
Mount engine: Use corrosion-resistant bolts and follow torque specifications.
Connect steering system: Install steering cable according to manufacturer instructions.
Connect control cables: Route throttle and shift cables without sharp bends.
Connect fuel system: Install fuel line with anti-siphon valve and water separator.
Connect electrical: Battery cables, trim/tilt wiring, and instrument connections.

WARNING! Engine weighs approximately 295 lbs; use proper lifting equipment. Ensure all connections are secure before operation.

Operation Procedures

Follow proper starting and operating procedures for optimal performance.

Pre-start check: Verify fuel level, oil level, and battery charge.
Starting procedure: Place in neutral, prime fuel system, turn key to start.
Warm-up: Allow engine to idle for 2-3 minutes before applying load.
Shifting: Always shift at idle speed; pause in neutral between forward and reverse.
Operation: Monitor temperature gauge and warning horn for overheating.
Shutdown: Allow engine to idle briefly before turning off ignition.

CAUTION! Always attach safety lanyard to operator. Never operate without proper water flow to pump.

Specifications

Horsepower: 90 HP at 5000 RPM
Cylinders: 4 (V4 configuration)
Displacement: 89.7 cubic inches (1470 cc)
Bore x Stroke: 3.50" x 2.30"
Ignition: CD electronic with 12V alternator
Fuel System: Dual carburetors
Fuel/Oil Ratio: 50:1 Evinrude/Johnson oil
Gear Ratio: 2.00:1
Weight: 295 lbs (approx.)
Full Throttle RPM: 4500-5500 RPM

Controls and Instrumentation

Remote control box includes: Key switch, choke, throttle, shift lever, trim/tilt switches, and safety lanyard connection.

Instrumentation: Tachometer, temperature gauge, voltmeter, fuel gauge, warning lights (oil, temperature, charging).

Trim/Tilt: Electric hydraulic system with up/down switches. Manual release valve for emergency lowering. Throttle: Friction adjustment for maintaining desired speed. Shift: Positive neutral safety switch prevents starting in gear.

Fuel System

Dual carburetors with fixed high-speed jets and adjustable low-speed mixture.

Fuel requirements: 87 octane minimum, ethanol-blended fuels acceptable with proper additives.
Oil mixture: 50:1 ratio with TC-W3 certified outboard oil.
Fuel filter: Replace annually or every 100 hours.
Carburetor adjustment: Initial setting 1-1/2 turns out from lightly seated.
Fuel pump: Diaphragm type, inspect annually for cracks or deterioration.

Tip: Use fuel stabilizer for storage periods exceeding 30 days.

Electrical System

12-volt system with 15-amp alternator output.

Battery: Minimum 450 CCA marine starting battery.
Charging system: 15-amp alternator maintains battery charge.
Ignition system: CD electronic with power pack and trigger assembly.
Starting system: 12V starter motor with solenoid.
Warning system: Temperature and oil warning horn.
Trim/tilt: Electric hydraulic pump with 20-amp fuse protection.

WARNING! Disconnect battery before servicing electrical components. Use marine-grade wiring and connectors.

Cooling System

Water pump impeller-driven cooling with thermostatic control.

Water pump: Replace impeller every 2 years or 300 hours.
Thermostat: Opens at 143°F (62°C), replace every 3 years.
Tell-tale: Visual stream indicates water pump operation.
Overheat protection: Warning horn sounds at 203°F (95°C).
Flushing: Use freshwater flush attachment after saltwater use.

CAUTION! Never operate engine without water supply to pump. Monitor tell-tale stream during operation.

Maintenance Schedule

Regular maintenance ensures long engine life and reliable operation.

Interval	Service Required
Every 100 hours	Change gear lube, inspect spark plugs
Annual	Replace water pump impeller, fuel filter
Every 2 years	Replace thermostat, inspect fuel lines
Every 3 years	Service carburetors, check timing
As needed	Grease fittings, check propeller condition

Storage Procedures

Proper storage prevents damage during extended non-use periods.

Fuel system: Add stabilizer and run engine to distribute through system.
Fogging: Spray fogging oil into carburetors while running, then into cylinders.
Cooling system: Flush with freshwater and drain completely.
Battery: Remove and store fully charged in cool, dry location.
Exterior: Wash thoroughly and apply protective wax coating.
Storage position: Store upright in dry, covered location.

CAUTION! Do not store with fuel in carburetors. Drain completely or use stabilizer.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, or compression	Check fuel supply, spark plugs, and compression test
Overheating	Water pump, thermostat	Replace water pump impeller, check thermostat operation
Poor performance	Fuel system, ignition	Clean carburetors, check spark advance, compression
No charging	Alternator, rectifier	Test stator output, check rectifier diodes
Trim/tilt failure	Hydraulic, electrical	Check fluid level, motor operation, relay function

Service: Contact authorized Evinrude dealer for technical support and genuine parts.

Parts: Use only genuine Evinrude replacement parts for optimal performance and warranty coverage.