1986 GL1200 Service Manual

The 1986 GL1200 is a touring motorcycle featuring a 1182cc liquid-cooled horizontally opposed four-cylinder engine, shaft drive, comprehensive instrumentation, air-assisted suspension, integrated fairing with audio system, and extensive touring amenities. This service manual covers maintenance procedures, specifications, troubleshooting, and repair information for proper servicing and upkeep of the motorcycle.

1. General Information 2. Maintenance Schedule 3. Engine Service 4. Fuel System 5. Electrical System 6. Chassis & Suspension 7. Brake System 8. Drive System 9. Troubleshooting 10. Specifications 11. Wiring Diagrams

General Information

Introduction to the 1986 GL1200 model, identification numbers, and safety precautions for service work.

Component	Description
Model Identification	GL1200A (Aspencade), GL1200I (Interstate)
Frame Number	Located on steering head
Engine Number	Located on crankcase left side
Safety Precautions	Use proper tools; disconnect battery; work in well-ventilated area
Service Tools	Metric tool set, torque wrench, special Honda tools as required

Maintenance Schedule

Recommended service intervals for optimal performance and longevity.

Every 600 miles/1000 km: Check oil level, tire pressure, brake operation
Every 4000 miles/6000 km: Change engine oil and filter, adjust drive chain
Every 8000 miles/12000 km: Replace air filter, check valve clearance
Every 16000 miles/24000 km: Replace spark plugs, check carburetor sync
Every 2 years: Replace brake fluid, check brake pads

WARNING! Always use genuine Honda parts for replacement. Follow torque specifications precisely.

Engine Service

Procedures for engine maintenance, repair, and overhaul.

Valve clearance adjustment: Check when engine is cold
Cylinder compression test: All cylinders should be within 10%
Timing belt replacement: Required every 60,000 miles
Oil change procedure: Use 10W-40 motorcycle oil
Cooling system service: Check radiator, hoses, and coolant level

CAUTION! Engine must be cool before performing service work. Use proper lifting equipment.

Fuel System

Carburetor Type: Four Keihin constant velocity CV carburetors
Fuel Capacity: 6.3 gallons (24 liters)
Fuel Type: Regular unleaded gasoline
Carburetor Sync: Required every 8,000 miles
Fuel Filter: Replace every 12,000 miles
Idle Speed: 950 ± 50 rpm
Float Level: 12.5mm specification

Electrical System

Battery, charging system, ignition, and accessory electrical components.

Battery: 12V 20Ah, maintain proper electrolyte level. Alternator: 350W output capacity. Starter: 12V DC electric starter with reduction gear.

Ignition: Transistorized electronic ignition with advance mechanism. Lights: 60/55W headlight, various indicator and position lights. Fuses: Main 30A, sub fuses 10A-15A located under left side cover.

Chassis & Suspension

Frame, steering, wheels, and suspension maintenance procedures.

Steering head bearing adjustment: Check for play every 4,000 miles
Wheel bearing inspection: Check for smooth rotation and no play
Swingarm pivot: Lubricate every 8,000 miles
Tire pressure: Front 36 psi, rear 41 psi (cold)
Fork oil change: Replace every 16,000 miles

Tip: Always use a motorcycle stand when working on wheels or suspension.

Brake System

Hydraulic disc brakes front and rear with integrated braking system.

Front brakes: Dual disc with twin-piston calipers
Rear brake: Single disc with single-piston caliper
Brake fluid: DOT 4, replace every 2 years
Pad thickness: Replace when less than 1mm remaining
Rotor thickness: Minimum 4.5mm front, 5.0mm rear
Brake bleeding: Use proper sequence - rear, then left front, right front
Integrated system: Rear brake pedal activates one front caliper

WARNING! Never reuse brake fluid. Always bleed system completely after opening.

Drive System

Shaft drive maintenance and service procedures.

Final drive: Hypoid gear type with oil bath. Drive shaft: Two universal joints requiring periodic lubrication. Rear gear oil: Change every 8,000 miles using 80W-90 gear oil.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Hard starting	Weak battery, fuel delivery	Check battery voltage; verify fuel flow to carbs
Poor idle	Dirty carbs, vacuum leak	Clean carburetors; check intake boots
Electrical failure	Stator, regulator	Test charging system output; check connections
Brake drag	Stuck calipers, contaminated fluid	Rebuild calipers; flush brake system
Vibration	Wheel balance, engine mounts	Balance wheels; check motor mount torque

Reset: Disconnect battery for 30 minutes to reset electronic systems.

Specifications

Engine Type: Liquid-cooled 4-stroke 4-cylinder horizontally opposed
Displacement: 1182cc
Bore x Stroke: 79.5mm x 66mm
Compression Ratio: 9.2:1
Power Output: 94 hp @ 7500 rpm
Torque: 79 lb-ft @ 5500 rpm
Transmission: 5-speed constant mesh
Final Drive: Shaft
Wheelbase: 63.8 inches
Weight: 759 lbs (wet)

Wiring Diagrams

Complete electrical schematics for main harness, charging system, ignition, lighting, and accessory circuits. Color-coded wiring with connector locations and ground points identified.

Service: Authorized Honda dealerships or qualified motorcycle technicians recommended for complex electrical repairs.