1988 Honda NX650 Manual

The 1988 Honda NX650 is a dual-sport motorcycle featuring a 644cc single-cylinder four-stroke engine, electric start, five-speed transmission, dual-purpose tires, and both on-road and off-road capabilities. This manual covers safety precautions, technical specifications, maintenance procedures, troubleshooting, and operational guidelines for proper ownership and maintenance of your NX650.

1. Features at a Glance 2. Safety Precautions 3. Technical Specifications 4. Maintenance Schedule 5. Controls and Instruments 6. Engine Operation 7. Electrical System 8. Troubleshooting 9. Storage and Care 10. Warranty Information

Features at a Glance

Key components: 644cc air-cooled single-cylinder engine, dual-purpose tires, electric start, five-speed transmission, front disc brake, rear drum brake.

Feature	Description
Engine Type	644cc air-cooled single-cylinder four-stroke
Starting System	Electric start with kick starter backup
Transmission	5-speed constant mesh
Front Suspension	Telescopic fork
Rear Suspension	Swingarm with dual shocks
Front Brake	Hydraulic disc
Rear Brake	Mechanical drum
Fuel Capacity	3.4 gallons (12.8 liters)
Seat Height	33.5 inches (850mm)
Weight	386 lbs (175kg) wet

Safety Precautions

Always wear proper protective gear and follow safe riding practices.

Always wear DOT-approved helmet, eye protection, gloves, and protective clothing.
Perform pre-ride inspection: check tires, brakes, lights, and controls.
Never operate under influence of alcohol or drugs.
Follow all traffic laws and regulations.

WARNING! Motorcycles offer no crash protection; ride defensively and assume other drivers don't see you.

Technical Specifications

Engine: 644cc air-cooled single-cylinder four-stroke
Bore x Stroke: 100.0 x 82.0 mm
Compression Ratio: 8.3:1
Carburetor: 38mm constant velocity
Ignition: CDI electronic
Transmission: 5-speed constant mesh
Final Drive: Chain
Front Tire: 90/90-21
Rear Tire: 120/90-17
Fuel Capacity: 3.4 gallons (12.8 liters)

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Service	Every 600 mi	Every 3,000 mi	Every 6,000 mi
Engine oil change	✓	✓	✓
Oil filter replacement		✓	✓
Air filter cleaning		✓	✓
Spark plug replacement			✓
Valve clearance check			✓
Chain adjustment	✓	✓	✓

Controls and Instruments

Familiarize yourself with all controls before riding.

Right Handlebar: Throttle, front brake lever, engine stop switch, start button.

Left Handlebar: Clutch lever, turn signals, horn, headlight dimmer.

Instrument Panel: Speedometer, odometer, trip meter, neutral indicator, high beam indicator, turn signal indicators.

Foot Controls: Gear shift lever (left), rear brake pedal (right).

Engine Operation

Proper starting and warm-up procedures ensure long engine life.

Check fuel valve is in ON position.
Turn ignition key to ON position.
Pull choke knob (cold starts only).
Pull clutch lever and press start button.
Allow engine to warm up before riding.
Push choke knob in as engine warms.

Tip: Avoid high RPM operation until engine reaches normal operating temperature.

Electrical System

12-volt DC system with battery and charging system.

Battery: 12V 10Ah
Charging System: AC generator with rectifier/regulator
Headlight: 60/55W halogen
Tail Light: 8W
Turn Signals: 21W each
Fuses: Main fuse 20A, spare fuses in fuse box

WARNING! Disconnect battery before performing electrical work to prevent shorts.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Engine won't start	Fuel, spark, or compression issue	Check fuel level, spark plug, and battery charge
Poor performance	Dirty air filter, clogged carburetor	Clean/replace air filter, clean carburetor jets
Electrical failure	Blown fuse, dead battery	Check fuses, test battery voltage
Chain noise	Loose or dry chain	Adjust chain tension, lubricate chain
Brake issues	Worn pads, air in lines	Inspect brake pads, bleed brake system

Storage and Care

Proper storage prevents damage during periods of non-use.

Fill fuel tank and add fuel stabilizer.
Change engine oil and filter.
Remove battery and store on trickle charger.
Clean entire motorcycle thoroughly.
Inflate tires to recommended pressure.
Store in dry, covered location.

CAUTION! Never store with fuel in carburetor float bowl to prevent gum formation.

Warranty Information

Honda limited warranty covers defects in materials and workmanship for 12 months from date of purchase with unlimited mileage. Warranty does not cover normal wear items, improper maintenance, or accident damage. Keep all maintenance records for warranty claims. Contact authorized Honda dealer for warranty service.