Category:
Mid-size Universal Japanese Motorcycle (UJM)
Target Audience:
Enthusiasts, mechanics, and owners seeking detailed repair and maintenance information.
Competitors 1981:
Yamaha XS650, Honda CB650, Suzuki GS650
Vehicle Platform:
Shaft-driven inline-four, known for smooth power delivery and reliability.
Manual Value Proposition:
Provides essential, factory-accurate information for maintaining and restoring a classic motorcycle.
Primary Coverage:
All mechanical and electrical systems of the 1981 Kawasaki KZ650
Secondary Coverage:
Troubleshooting, routine maintenance, specifications, and parts diagrams
Estimated Page Count:
Approximately 300-400 pages (typical for this era/model)
Type:
Factory Service Repair Manual
Format:
Digital (likely PDF, implied by modern sales)
Engine:
Complete engine disassembly, assembly, inspection, and repair, including timing, valve clearance, and carburetor synchronization.
Transmission:
Gearbox operation, inspection, repair, and shift mechanism adjustment.
Fuel System:
Carburetor overhaul, jetting specifications, fuel tank, and fuel pump (if applicable).
Ignition System:
Ignition timing, points (if applicable), CDI unit, spark plugs, and wiring diagrams.
Electrical System:
Lighting, charging system (stator, rectifier/regulator), battery, starter motor, horn, and all switchgear.
Brakes:
Front and rear brake systems, including disc and caliper inspection, pad replacement, hydraulic system bleeding, and master cylinder overhaul.
Suspension:
Front fork (telescopic) overhaul, oil replacement, seal replacement, and rear shock absorber inspection and adjustment.
Steering:
Steering head bearing inspection and adjustment, handlebar mounting.
Wheels And Tires:
Wheel bearing inspection and replacement, tire pressure recommendations, and wheel removal/installation.
Frame And Bodywork:
Frame inspection, seat removal, fuel tank removal, and minor body panel adjustments.
Maintenance:
Oil changes, filter replacement, chain adjustment, lubrication points, and general pre-ride inspections.
Troubleshooting:
Systematic diagnostic procedures for common performance issues, electrical faults, and starting problems.
Repair:
Detailed step-by-step instructions for component removal, disassembly, repair, reassembly, and installation.
Adjustments:
Carburetor synchronization, valve clearance, chain tension, brake lever free play, and clutch adjustment.
Depth:
Comprehensive, covering everything from basic maintenance to complete engine rebuilds and electrical system diagnostics.
Digital Format:
PDF (searchable text highly desirable)
Image Resolution:
High resolution for clear diagrams and text (typical for factory publications)
Original Binding:
Staple-bound or perfect-bound (for physical copies)
Original Paper Quality:
Durable, glossy paper designed for workshop use
Type:
Inline-four cylinder, air-cooled, DOHC
Displacement:
652 cc (652 cubic centimeters)
Bore X Stroke:
62.0 mm x 54.0 mm (typical for this generation)
Compression Ratio:
9.2:1 (typical)
Horsepower Estimated:
Approx. 64-68 hp at 9000 rpm (varies slightly by market/tune)
Torque Estimated:
Approx. 37-40 lb-ft at 7000 rpm (varies)
Carburetors:
Four Keihin CVK constant velocity carburetors (e.g., 28mm or 30mm, model specific)
Fuel Capacity:
Approx. 3.7 US gallons (14 liters)
Oil Type Recommendation:
API SE, SF, or SG; SAE 10W-40 or 20W-50 motorcycle specific oil
Oil Capacity W Filter:
Approx. 3.0 US quarts (2.8 liters)
Length Overall:
Approx. 85.0 inches (2160 mm) - varies by model variant
Width Handlebar:
Approx. 32.0 inches (815 mm) - varies by model variant
Height Seat:
Approx. 47.0 inches (1195 mm) - varies by model variant
Dry Weight Estimated:
Approx. 450-470 lbs (204-213 kg)
Wet Weight Estimated:
Approx. 475-500 lbs (215-227 kg)
Era Safety Standards:
Reflects 1980s motorcycle safety standards; no formal crash ratings as with modern cars.
Braking System:
Front and rear disc brakes for enhanced stopping power compared to drum systems.
Lighting:
Headlight, taillight, brake lights, turn signals for visibility.
Frame Construction:
Steel tube frame designed for stability and rigidity.
Tire Design:
Tubed tires, common for the era, with emphasis on road grip.
Oil Change Interval:
Every 3,000 miles (4,800 km) or 6 months, whichever comes first.
Valve Clearance Check:
Every 6,000 miles (9,600 km) or 12 months.
Spark Plug Replacement:
Every 6,000 miles (9,600 km) or as needed based on inspection.
Chain Adjustment Lubrication:
Every 600 miles (1,000 km) or after washing/rain.
Brake Fluid:
DOT 3 or DOT 4 hydraulic brake fluid (ensure compatibility).
Fork Oil:
Kawasaki KHL15-10 (10W) or equivalent motorcycle fork oil; 393 ml per fork leg.
Common Problems General:
Carburetor synchronization drift, potential for cam chain noise with age, fork seal leaks, electrical connections corrosion.
Maintenance Focus Areas:
Regular cleaning and synchronization of carburetors, periodic inspection of ignition components, and proactive fork maintenance are key.
Kawasaki Motorcycle History:
Kawasaki has a long-standing reputation for producing powerful and innovative motorcycles across various categories.
Kz650 Lineage:
The KZ650 series was a significant evolution from earlier Kawasaki models, offering a refined inline-four engine and shaft drive, bridging the gap between smaller displacement bikes and the larger KZ900/KZ1000.
1981 Specifics:
The 1981 model is often designated as the KZ650-D2 and typically includes the CSR (Custom Sport Ride) variant, which featured styling updates like a bikini fairing, cast wheels, and revised styling.
Production Years Kz650:
1977-1983
Historical Market Perception:
The KZ650 was well-received for its smooth power, reliability, and more manageable size compared to larger superbikes of the era.
Magazine Reviews Era:
Often praised for its balance of performance and handling, making it a popular choice for general sport riding and commuting.
Manual Certification:
Factory Service Manual - indicating official, manufacturer-approved repair procedures.
