1986 4 hp Johnson Deluxe Service Manual

The 1986 4 hp Johnson Deluxe outboard motor is a compact two-cylinder engine featuring electric start, 12V charging system, thermostat cooling, single carburetor, CD ignition system, gear shift (forward-neutral-reverse), water pump impeller cooling, and corrosion-resistant components. This service manual covers maintenance procedures, specifications, troubleshooting, and repair instructions for proper operation and longevity. Below are key sections for specifications, maintenance, troubleshooting, and repair procedures.

1. Specifications 2. Maintenance Schedule 3. Fuel System 4. Ignition System 5. Cooling System 6. Gearcase & Propeller 7. Electrical System 8. Troubleshooting 9. Storage & Winterization 10. Safety Precautions 11. Parts & Service

Specifications

Technical specifications for the 1986 4 hp Johnson Deluxe outboard motor.

Specification	Details
Horsepower	4 hp at 4500 RPM
Cylinders	2 cylinders in-line
Displacement	7.4 cubic inches (121 cc)
Bore x Stroke	2.125" x 1.625"
Ignition System	CD (Capacitor Discharge)
Starting System	Electric start with recoil backup
Gear Ratio	13:26 (2.00:1)
Fuel/Oil Ratio	50:1 (TC-W3 oil)
Full Throttle RPM	4500-5500 RPM
Weight	Approx. 55 lbs

Maintenance Schedule

Regular maintenance procedures and intervals for optimal performance.

Check gearcase oil: Every 100 hours or annually; replace if milky.
Replace spark plugs: Every 100 hours or seasonally (Champion L77JC4).
Inspect water pump: Every 2 years or 200 hours; replace impeller if worn.
Fuel system: Clean carburetor annually; replace fuel filter every season.
Grease fittings: Apply marine grease to steering pivot and tilt points.

WARNING! Always disconnect spark plug wires before servicing to prevent accidental starting.

Fuel System

Carburetor adjustment and fuel system maintenance procedures.

Fuel mixture: Use 50:1 gasoline to TC-W3 outboard oil ratio.
Carburetor adjustment: Initial setting - 1-1/2 turns out from lightly seated.
Idle speed adjustment: Set to 650-750 RPM in forward gear (in water).
Fuel pump: Inspect diaphragm for cracks; replace if leaking.
Fuel tank: Use clean, fresh fuel; stabilize if storing over 30 days.

CAUTION! Gasoline is flammable; work in well-ventilated area away from sparks.

Ignition System

CD ignition system testing and spark plug specifications.

Spark Plugs: Champion L77JC4, gap 0.030"
Ignition Timing: Fixed at 18° BTDC at WOT
Power Pack: Output 25,000 volts minimum
Stop Switch: Tests for continuity when pressed
Charge Coil: Resistance 650-850 ohms

Test spark with gap tester; should jump 7/16" gap. Replace power pack if weak spark.

Cooling System

Thermostat and water pump maintenance for proper engine cooling.

Thermostat: Opens at 143°F; test in hot water; replace if stuck.
Water pump: Replace impeller every 2 years; inspect housing for wear.
Tell-tale stream: Check for steady flow at all speeds; clean if restricted.
Overheat warning: Engine will lose power if overheating occurs.

WARNING! Never run engine without water supply; impeller will burn quickly.

Gearcase & Propeller

Gearcase service and propeller maintenance procedures.

Gearcase Oil: Use OMC/BRP Hi-Vis gear lube; capacity 2.5 oz.

Drain oil: Remove upper and lower screws; inspect for metal particles.
Refill: Pump oil from bottom until clean oil emerges from top vent.
Propeller: Inspect for fishing line damage; replace shear pin if sheared.
Shift linkage: Adjust for positive engagement in forward and reverse.

Electrical System

12V charging system and electric start components.

Component	Specification
Battery	12V, minimum 25 Ah
Alternator	6 amp charging output
Starter Motor	12V, clockwise rotation
Voltage Regulator	14.2-14.8V regulated output
Fuse	20 amp in positive cable

Test charging voltage: 13.5-15V at 1500 RPM. Clean battery connections regularly.

Troubleshooting

Common problems and solutions for the 4 hp Johnson outboard.

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, or compression	Check fuel flow, spark plugs, compression (should be 100+ psi)
Runs rough at idle	Carburetor adjustment	Clean carburetor; adjust idle mixture screw
Overheating	Water pump or thermostat	Replace water pump impeller; test thermostat
No charging	Stator or rectifier	Test stator output (18-22V AC at 1500 RPM)
Hard shifting	Shift linkage adjustment	Adjust shift rod length per manual specification

Storage & Winterization

Proper procedures for seasonal storage and winterization.

Fuel system: Add fuel stabilizer; run engine 10 minutes to circulate.
Drain carburetor: Close fuel valve; run engine until it stops.
Fogging oil: Remove spark plugs; spray fogging oil into cylinders.
Gearcase: Change gear oil to check for water contamination.
Battery: Remove and store fully charged in cool, dry location.

CAUTION! Store in upright position to prevent oil migration.

Safety Precautions

Important safety information for operation and maintenance.

Always wear USCG-approved life jacket when operating
Ensure ventilation when running in enclosed areas
Keep hands clear of propeller when engine is running
Use proper lifting techniques - engine weighs 55 lbs
Install engine kill switch lanyard when operating

WARNING! Carbon monoxide from exhaust can be fatal in enclosed spaces.

Parts & Service

Genuine Johnson parts and authorized service information.

Use only genuine OMC/BRP parts for optimal performance and warranty coverage. For technical assistance or parts ordering, contact:

Johnson Customer Service: 1-800-AT-JOHNSON

Parts Diagrams: Available at authorized Johnson dealers

Technical Bulletins: Check for service updates and recalls