1986 Honda Nighthawk 700 Repair Manual

The 1986 Honda Nighthawk 700 is a four-cylinder standard motorcycle featuring a 697cc liquid-cooled DOHC engine, shaft drive, hydraulic disc brakes front and rear, ComStar wheels, and a unique parallelogram rear suspension system. This repair manual covers maintenance, troubleshooting, and repair procedures for all major systems including engine, transmission, electrical, brakes, and suspension. Below are key sections for specifications, maintenance schedules, troubleshooting, and step-by-step repair procedures.

1. Specifications 2. Maintenance Schedule 3. Engine Repair 4. Transmission & Drive System 5. Electrical System 6. Brake System 7. Suspension & Steering 8. Fuel System 9. Troubleshooting Guide 10. Safety Precautions

Specifications

Technical specifications for the 1986 Honda Nighthawk 700.

Component	Specification
Engine Type	697cc liquid-cooled 4-stroke 16-valve DOHC inline-four
Bore x Stroke	70.0mm x 45.4mm
Compression Ratio	10.0:1
Fuel System	Four 34mm constant velocity carburetors
Ignition System	CDI electronic ignition
Transmission	5-speed constant mesh
Final Drive	Shaft drive
Front Suspension	Air-assisted telescopic fork
Rear Suspension	Pro-Link parallelogram system
Front Brake	Dual hydraulic disc
Rear Brake	Single hydraulic disc
Fuel Capacity	5.3 gallons (20 liters)
Weight	529 lbs (240 kg) wet

Maintenance Schedule

Recommended maintenance intervals for optimal performance.

Every 600 miles/1000 km: Check oil level, tire pressure, chain tension, brake fluid
Every 4,000 miles/6,400 km: Change engine oil and filter
Every 8,000 miles/12,800 km: Adjust valve clearance, sync carburetors
Every 12,000 miles/19,200 km: Replace spark plugs, air filter
Every 16,000 miles/25,600 km: Change brake fluid, check brake pads
Every 2 years: Replace coolant

WARNING! Always use genuine Honda parts and recommended fluids for maintenance.

Engine Repair

Step-by-step procedures for engine maintenance and repair.

Valve Adjustment: Remove valve cover, set piston at TDC compression, adjust clearance to 0.005 in (0.13 mm) intake, 0.006 in (0.15 mm) exhaust
Oil Change: Warm engine, drain oil, replace filter, refill with 3.7 quarts SAE 10W-40
Coolant Replacement: Drain radiator and engine, flush system, refill with 50/50 coolant mix
Carburetor Sync: Connect vacuum gauges, adjust synchronization screws for equal vacuum
Spark Plug Replacement: Use NGK DPR8EA-9, gap to 0.028-0.031 in (0.7-0.8 mm)

CAUTION! Allow engine to cool before performing maintenance to prevent burns.

Transmission & Drive System

Transmission service and shaft drive maintenance.

Transmission Oil: Check level monthly, change every 8,000 miles with 80W-90 gear oil
Clutch Adjustment: Adjust cable free play to 0.4-0.6 in (10-15 mm) at lever
Shaft Drive: Check fluid level, change every 16,000 miles with hypoid gear oil
Shift Mechanism: Inspect shift linkage, replace worn components
Neutral Switch: Test continuity, replace if faulty

Electrical System

Troubleshooting and repair of electrical components.

Battery: 12V 14Ah, maintain specific gravity at 1.260-1.280

Charging System: Stator output 14V AC at 5000 RPM, regulator/rectifier test procedures

Ignition System: Check pulse generator resistance (450-550 ohms), ignition coil primary (2-4 ohms)

Lighting: Headlight 60/55W, turn signals 21W, brake light 21/5W

Starter: Draw current max 100A, brush length min 0.315 in (8 mm)

Brake System

Hydraulic brake system maintenance and repair.

Check brake fluid level monthly, use DOT 4 fluid
Inspect brake pads for wear, replace if thickness < 0.08 in (2 mm)
Bleed brake system annually or when spongy feel occurs
Check brake disc thickness, replace if < 0.157 in (4 mm)
Inspect brake lines for cracks or leaks

Tip: Always clean brake components with brake cleaner, never petroleum-based solvents.

Suspension & Steering

Front fork and rear suspension service procedures.

Front Fork: Oil capacity 16.9 oz (500 ml) per leg, use SAE 10W fork oil

Rear Shock: Preload adjustment 5 positions, check for oil leaks

Steering Head Bearings: Check for play, adjust torque to 18 ft-lbs (25 Nm)

Wheel Bearings: Check for smooth rotation, replace if rough or noisy

Tire Pressure: Front 28 psi (190 kPa), rear 32 psi (220 kPa)

Fuel System

Carburetor service and fuel system maintenance.

Clean fuel filter annually
Drain carburetor float bowls for storage
Adjust idle speed to 1100 ± 100 RPM
Check fuel line condition, replace if cracked
Clean air filter element, replace if damaged

WARNING! Work in well-ventilated area, no smoking near fuel system components.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Hard starting	Weak battery, dirty carbs	Charge battery, clean carburetors
Poor idle	Vacuum leak, sync needed	Check hoses, sync carburetors
Overheating	Low coolant, stuck thermostat	Check coolant level, test thermostat
Electrical failure	Bad regulator, stator	Test charging system components
Brake drag	Stuck caliper, contaminated fluid	Clean calipers, bleed system
Transmission noise	Low oil, worn gears	Check oil level, inspect gears

Reset: Disconnect battery for 30 minutes to reset ECU if applicable.

Service: Contact authorized Honda dealer for complex repairs.

Safety Precautions

Essential safety guidelines for motorcycle repair.

Always use proper jack stands when lifting motorcycle
Wear safety glasses when working with chemicals or under vehicle
Disconnect battery before electrical work
Allow exhaust system to cool before working near it
Use torque wrench for critical fasteners
Keep work area clean and organized

CAUTION! Never work on motorcycle while engine is running unless specified in procedure.