1987 90 hp Evinrude Outboard Manual

The 1987 90 hp Evinrude Outboard is a V4 two-stroke marine engine featuring loop charging, 90° cylinder bank, cross-flow scavenging, thermostatically controlled cooling, capacitor discharge ignition, and built-in fuel pump. Below are key sections for safety, features, installation, operation, maintenance, troubleshooting, and specifications.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Operation 6. Maintenance Schedule 7. Fuel System 8. Electrical System 9. Cooling System 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: V4 cylinder configuration, 90 horsepower rating, CD ignition system, built-in fuel pump, thermostatic cooling, power trim/tilt.

Feature	Description
Engine Type	V4 two-stroke outboard
Displacement	99.6 cubic inches (1.6L)
Bore x Stroke	3.50" x 2.60"
Ignition System	Capacitor Discharge (CD)
Fuel System	Built-in mechanical fuel pump
Cooling System	Thermostatically controlled water pump
Gear Ratio	14:27 (1.93:1)
Starting System	Electric start with alternator
Weight	Approximately 295 lbs
Full Throttle RPM	4500-5500 RPM

Installation

Proper installation ensures optimal performance and safety.

Mounting: Select appropriate transom height; use marine-grade mounting hardware.
Steering: Connect steering system according to boat manufacturer specifications.
Electrical: Connect battery with proper polarity; install 50-amp fuse in positive cable.
Fuel System: Install fuel line with quick-connect fittings; prime system.
Control Cables: Connect throttle and shift cables with proper adjustment.

WARNING! Engine is heavy; use proper lifting equipment. Ensure transom can support engine weight.

First-Time Setup

Initial setup procedures for new installation.

Fuel Mix: Use 50:1 fuel/oil ratio with TC-W3 certified outboard oil.
Priming: Squeeze fuel primer bulb until firm.
Battery: Connect fully charged 12V marine battery.
Water Supply: Connect flush device or lower engine into water.
Initial Start: Advance throttle to start position; turn key to start.
Break-in: Follow break-in procedure for first 10 hours of operation.

CAUTION! Never run engine without water supply to impeller. Follow break-in procedure exactly.

Specifications

Horsepower: 90 hp at 5000 RPM
Cylinders: 4 (V4 configuration)
Displacement: 99.6 cu in (1632 cc)
Bore: 3.50 inches (88.9 mm)
Stroke: 2.60 inches (66.0 mm)
Ignition: Capacitor Discharge with alternator
Fuel: 87 octane minimum, 50:1 oil ratio
Alternator: 16 amp output
Gear Ratio: 14:27 (1.93:1)
Propeller: 13" x 17" standard aluminum

Controls and Operation

Control panel features: Key switch, choke, trim/tilt switch, throttle/shift control.

Starting Procedure: Ensure gear in neutral, advance throttle to start position, turn key while pushing in for choke if cold.

Operation: Allow engine to warm up at idle. Monitor temperature and oil injection. Use trim/tilt for optimal boat performance.

Shutdown: Return to idle speed, turn key to off position. Allow engine to cool before covering.

Maintenance Schedule

Regular maintenance ensures long engine life and reliable operation.

Interval	Service Required
Every 100 hours	Change gear lube, inspect spark plugs
Every 200 hours	Replace water pump impeller
Annual	Fuel filter replacement, corrosion inspection
Every 2 years	Thermostat replacement
As needed	Propeller inspection, anode replacement

Fuel System

Built-in mechanical fuel pump with carburetor system.

Fuel Requirements: 87 octane gasoline with TC-W3 outboard oil at 50:1 ratio
Fuel Pump: Mechanical diaphragm type - inspect annually
Carburetors: Four fixed-jet carburetors - synchronize annually
Fuel Filter: Replace annually or when contaminated
Primer System: Manual primer bulb for initial fuel delivery

WARNING! Use only approved marine fuels. Never use automotive oil in fuel mixture.

Electrical System

12V DC system with CD ignition and 16 amp alternator.

Battery: Minimum 450 CCA marine starting battery
Alternator: 16 amp output at 5000 RPM
Ignition: Capacitor Discharge with power pack
Spark Plugs: Champion QL77JC4 gapped at 0.030"
Starter: 12V positive engagement type
Fuse: 50 amp main fuse in starter circuit

Cooling System

Water pump cooling with thermostatic control.

Water Pump: Rubber impeller type - replace every 200 hours
Thermostat: Opens at 143°F (62°C) - test annually
Tell-tale: Water stream indicator for cooling verification
Overheat Protection: Audio warning horn activates at 203°F (95°C)

CAUTION! Always check for water discharge from tell-tale. Never run engine without water supply.

Regulatory Information

EPA certified for marine use. Manufactured by Outboard Marine Corporation. Meets US Coast Guard requirements for marine engines. For technical support, contact Evinrude Customer Service at 1-800-334-6542 or visit authorized Evinrude dealerships.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, or compression	Check fuel delivery, spark plugs, compression test
Overheating	Water pump, thermostat	Replace water pump impeller, test thermostat
Poor performance	Fuel system, ignition	Clean carburetors, check spark plugs and timing
No spark	Ignition components	Test power pack, stator, trigger assembly
Hard starting	Choke system, fuel delivery	Check choke operation, fuel pump, primer bulb

Service: Contact authorized Evinrude dealer for major repairs. Technical support: 1-800-334-6542