Era:
Late 1970s to mid-1980s Japanese motorcycle market
Target Audience:
Enthusiast owners, independent mechanics, restoration specialists
Competitors Class:
4-cylinder middleweights, inline-fours from Yamaha, Kawasaki, Suzuki
Vehicle Strengths:
Smooth inline-four engine, comfortable ergonomics, reliable Honda engineering
Manual Value Proposition:
Empowers owners to maintain and repair their vintage Honda CB650 with confidence
Years Covered:
1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985
Estimated Page Count:
300+
Type:
Complete Workshop Service & Repair Manual
Engine:
Complete disassembly, inspection, overhaul, troubleshooting, tuning
Fuel System:
Carburetor overhaul and adjustment (VM/CV types), fuel tank, fuel pump
Transmission:
Gearbox disassembly, assembly, inspection, clutch service
Electrical System:
Ignition system, charging system (stator, regulator/rectifier), starter motor, battery, lighting, wiring diagrams
Suspension:
Front forks (seals, oil, springs), rear shock absorbers, swingarm
Brakes:
Front and rear brake system maintenance, disc brake caliper service, master cylinder overhaul, fluid replacement
Cooling System:
Air-cooled engine specifications, oil cooling system components (if applicable)
Frame And Bodywork:
Frame inspection, body panel removal and installation, seat, handlebars, fenders
Wheels And Tires:
Wheel bearing service, tire replacement, spoke tensioning
Exhaust System:
Exhaust pipe and muffler inspection and replacement
Maintenance:
Regular service, oil changes, filter replacement, chain adjustment, spark plug replacement, valve clearance adjustment
Troubleshooting:
Diagnostic flowcharts for common running issues, electrical faults, starting problems
Repair:
Step-by-step instructions for component overhaul and replacement
Rebuilds:
Engine, transmission, and carburetor complete rebuild procedures
Adjustments:
Carburetor synchronization, ignition timing, clutch and brake lever adjustments, suspension adjustments
Depth:
Comprehensive from basic maintenance to complete engine rebuilds and advanced diagnostics
Diagrams Included:
Detailed exploded views, wiring diagrams, torque specifications
Type:
Air-cooled, 4-stroke, DOHC, inline-four
Displacement:
626 cc (38.2 cu in)
Bore X Stroke:
62.0 mm x 50.6 mm (2.44 in x 1.99 in)
Horsepower Output:
Approx. 64 HP (47.7 kW) at 9,000 RPM (varies by year/spec)
Torque Output:
Approx. 35 lb-ft (47.5 Nm) at 7,000 RPM (varies by year/spec)
Carburetion:
4 x Keihin constant velocity (CV) carburetors (e.g., 28mm)
Fuel Delivery:
Gravity feed from fuel tank via petcock
Fuel Type:
Unleaded gasoline, 87 octane or higher recommended
Type:
Electronic ignition (CDI) with breaker points in early models, then fully electronic
Oil Capacity:
Approx. 3.5 Liters (3.7 US qt) with filter change
Recommended Oil:
API SE, SF or SG, SAE 10W-40 motorcycle oil
Type:
6-speed, constant mesh, sequential manual transmission
Clutch Type:
Wet, multi-plate
Final Drive:
O-ring sealed chain drive
Gear Ratios:
Specific ratios detailed in manual (e.g., 1st: 2.733, 2nd: 1.944, 3rd: 1.545, 4th: 1.273, 5th: 1.074, 6th: 0.917)
Safety Standards:
N/A (Motorcycle, pre-dates modern standardized ratings)
Braking System:
Dual front disc brakes, single rear disc brake (caliper and master cylinder details covered)
Lighting:
Halogen headlamp, tail/brake lights, turn signals (wiring and bulb replacement)
Frame Construction:
Steel semi-double cradle frame
Features:
N/A (Classic motorcycle, pre-infotainment era)
Features:
N/A (Classic motorcycle, pre-driver assistance era)
Features:
N/A (Classic motorcycle, pre-connectivity era)
Gauge Cluster:
Analog speedometer, tachometer, fuel gauge, indicator lights (manual covers diagnosis and repair)
Oil Change:
Every 3,000 miles (4,800 km) or 6 months, whichever comes first
Filter Replacement:
With every oil change
Valve Adjustment:
Every 6,000 miles (9,600 km) or 12 months
Spark Plug Replacement:
Every 12,000 miles (19,200 km) or 24 months
Brake Fluid:
DOT 3 or DOT 4 hydraulic brake fluid
Coolant Type:
Air-cooled engine (no coolant)
Chain Lube:
Recommended chain lubricant
Carburetor Issues:
Vaccum slide wear, jet clogging, synchronization drift (addressed in manual)
Electrical Issues:
Regulator/rectifier failure, CDI unit issues, wiring harness degradation (covered in troubleshooting)
Engine Wear:
Cam chain wear, piston ring wear (manual provides wear limits and inspection procedures)
Suspension Wear:
Fork seal leaks, rear shock absorber degradation (covered in fork and shock service)
Honda Motorcycles:
Honda's legacy of reliable, innovative, and performance-oriented motorcycles
Cb650 Predecessors:
Evolved from the CB550 series, representing Honda's push for larger displacement inline-fours
Cb650 Variants:
Offered in standard (CB650) and Custom (CB650 Custom) trims, differing primarily in styling and features like spoke wheels vs. cast wheels, and exhaust configurations.
Production Period:
1978-1985
Manufacturing Location:
Japan
