1987 Honda Magna Service Manual

The 1987 Honda Magna is a V4-powered cruiser motorcycle featuring liquid cooling, shaft drive, and a 700cc engine. This service manual covers maintenance procedures, specifications, troubleshooting, and repair instructions for the complete motorcycle system including engine, transmission, electrical, chassis, and fuel systems. Below are key sections for safety, maintenance schedules, technical specifications, and repair procedures.

1. Features and Specifications 2. Safety Precautions 3. Maintenance Schedule 4. Technical Specifications 5. Engine Service 6. Transmission and Drive 7. Electrical System 8. Fuel System 9. Chassis and Suspension 10. Troubleshooting 11. Wiring Diagrams

Features and Specifications

Key components: 700cc liquid-cooled V4 engine, shaft final drive, hydraulic disc brakes front and rear, electronic ignition, dual exhaust system.

Feature	Description
Engine Type	Liquid-cooled 4-stroke 90° V4
Displacement	700cc
Bore x Stroke	70.0 x 45.4mm
Compression Ratio	10.5:1
Fuel System	Four 32mm constant velocity carburetors
Ignition System	Fully transistorized electronic
Transmission	6-speed constant mesh
Final Drive	Shaft drive
Front Suspension	Telescopic fork
Rear Suspension	Dual shocks with adjustable preload

Safety Precautions

Always follow safety procedures when servicing your motorcycle.

Work in a well-ventilated area when working with fuel or chemicals.
Use proper tools and safety equipment including gloves and eye protection.
Support motorcycle securely on center stand or lift before beginning work.
Disconnect battery before performing electrical work.

WARNING! Gasoline is highly flammable; keep away from sparks and open flames. Engine and exhaust components become extremely hot during operation.

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Pre-ride inspection: Check tires, brakes, lights, and fluid levels before each ride.
Every 600 miles/1000 km: Check and adjust chain slack, lubricate chain.
Every 4000 miles/6000 km: Change engine oil and filter, check valve clearance.
Every 8000 miles/12000 km: Replace spark plugs, clean air filter, check brake pads.
Annual: Change brake fluid, check battery condition and terminals.

CAUTION! Always use genuine Honda parts or equivalent quality replacements.

Technical Specifications

Overall Length: 90.2 inches (2290mm)
Overall Width: 32.7 inches (830mm)
Overall Height: 45.7 inches (1160mm)
Wheelbase: 62.2 inches (1580mm)
Seat Height: 29.5 inches (750mm)
Ground Clearance: 5.9 inches (150mm)
Curb Weight: 529 lbs (240kg)
Fuel Capacity: 4.2 gallons (16 liters)
Oil Capacity: 3.7 quarts (3.5 liters) with filter change

Engine Service

Engine maintenance procedures including valve adjustment, oil changes, and cooling system service.

Valve Clearance: Intake: 0.004-0.005 in (0.10-0.13mm), Exhaust: 0.005-0.006 in (0.13-0.15mm). Adjust when engine is cold.

Oil Change: Use SAE 10W-40 motorcycle oil. Drain when warm, replace filter, torque drain plug to 22 ft-lbs (30 Nm). Cooling System: Check coolant level in reservoir, use 50/50 mix of antifreeze and distilled water. Spark Plugs: NGK DPR8EA-9, gap 0.031-0.035 in (0.8-0.9mm).

Transmission and Drive

6-speed transmission maintenance and shaft drive service procedures.

Transmission oil: Check level with motorcycle upright, use SAE 10W-40 motorcycle oil.
Shift mechanism: Lubricate linkage points periodically with grease.
Shaft drive: Check final drive oil level, replace every 16,000 miles.
Clutch: Adjust free play at lever to 0.4-0.8 in (10-20mm).

Tip: Always check for oil leaks around transmission and final drive seals.

Electrical System

Battery, charging system, ignition, and lighting maintenance.

Battery: 12V 14Ah, check specific gravity 1.260-1.280, keep terminals clean.
Charging system: Output 350W at 5000 rpm, check voltage 13.5-15.0V at 5000 rpm.
Fuses: Main 30A, Headlight 15A, Signal 10A, Ignition 10A.
Bulbs: Headlight 60/55W, Brake/Tail 27/8W, Turn Signal 23W.

WARNING! Disconnect battery negative terminal first when performing electrical work.

Fuel System

Carburetor adjustment, fuel filter replacement, and tank maintenance.

Carburetor synchronization: Use vacuum gauges to balance all four carburetors.
Fuel filter: Replace every 12,000 miles or if flow is restricted.
Idle speed: Adjust to 1000 ± 100 rpm when engine is warm.
Fuel mixture: Pilot screw factory setting 2-1/8 turns out from lightly seated.
Float level: Check and adjust to specification if flooding occurs.

WARNING! Work in well-ventilated area when servicing fuel system components.

Chassis and Suspension

Frame, suspension, brakes, and wheel maintenance procedures.

Front Suspension: Fork oil capacity 177ml per leg, use SAE 10W fork oil. Rear Suspension: Adjust preload to match load and riding conditions. Brakes: Front dual disc, rear single disc, check pad thickness, replace if less than 0.04 in (1mm). Tires: Front 110/90-18, Rear 140/90-15, pressure 28 psi front, 32 psi rear. Steering Head: Check for play, adjust bearings if necessary.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Battery, fuel, spark	Check battery voltage, fuel flow, spark plug condition.
Poor idle	Carburetor sync, air filter	Synchronize carburetors, clean/replace air filter.
Electrical failure	Battery, fuses, connections	Test battery, check all fuses, clean connections.
Brake problems	Pads, fluid, air in system	Check pad thickness, fluid level, bleed brakes if spongy.
Transmission issues	Oil level, clutch adjustment	Check oil level, adjust clutch free play.

Note: Always diagnose systematically from simplest to most complex causes.

Wiring Diagrams

Complete electrical schematics for the 1987 Honda Magna showing all circuits, connectors, and component locations. Diagrams include color coding for easy wire identification and troubleshooting.

Service Support: For technical assistance or parts ordering, contact authorized Honda dealership or visit Honda's technical support website.