Market Segment:
Sportbike / Supersport
Key Competitors 1985:
Yamaha FZ400, Honda CBR400F, Kawasaki GPZ400R.
Bike Strengths:
Known for its sporty handling, V-engine configuration (on some variants), and competitive performance for its class and era.
Manual Benefit:
Enables owners and technicians to perform accurate repairs, diagnostics, and maintenance, ensuring optimal performance and longevity of the classic GSXR400.
Target Audience:
Suzuki GSXR400 GK71B owners, independent motorcycle mechanics, restoration specialists.
Engine:
Complete engine disassembly, assembly, repair, overhaul, including cylinder head, pistons, crankshaft, valvetrain, lubrication system, cooling system.
Fuel System:
Carburetor identification, adjustment, overhaul, fuel pump, fuel lines, fuel tank.
Electrical System:
Ignition system (CDI, coils, spark plugs), charging system (alternator, regulator/rectifier), starting system (starter motor, battery), lighting, instrumentation, wiring diagrams.
Transmission Drive:
Gearbox overhaul, clutch operation, drive chain and sprockets maintenance and replacement.
Suspension Steering:
Front forks (suspension, damping, seals), rear shock absorber, steering head bearings, linkage.
Brakes:
Front and rear brake system inspection, service, fluid replacement, caliper overhaul, master cylinder, hydraulic lines.
Bodywork Frame:
Frame inspection, fairings, seat, fuel tank, body panel removal and installation.
Wheels Tires:
Wheel bearing inspection and replacement, tire pressure, tire replacement.
Routine Maintenance:
Oil changes, filter replacement, chain adjustment, lubrication points, spark plug checks, brake fluid checks.
Troubleshooting:
Diagnostic charts, common problems, causes, and solutions for various systems.
Disassembly Assembly:
Detailed step-by-step instructions for component removal and reinstallation.
Rebuilds:
Comprehensive instructions for major component rebuilds, including engine and transmission.
Technical Depth:
Factory specifications, OEM tolerances, torque values, electrical data, component testing procedures, detailed diagrams.
Engine Type:
Liquid-cooled, 4-stroke, DOHC, Inline-4 cylinder
Bore X Stroke:
56.0 mm x 40.2 mm (typical for GK71B, consult manual for exact)
Compression Ratio:
11.5:1 (typical, consult manual)
Horsepower Ps:
Approximately 50-59 PS (at crankshaft) depending on market and tuning (consult manual for precise figures).
Torque Nm:
Approximately 38-42 Nm (at crankshaft) (consult manual for precise figures).
Carburetion:
Mikuni VM Series or similar constant velocity carburetors (e.g., 4 x Mikuni CVKD32).
Fuel Type:
Unleaded gasoline
Oil Type:
API SG or higher, SAE 10W-40 motorcycle specific oil recommended (verify with manual).
Coolant Type:
Ethylene glycol based coolant with distilled water (typically 50/50 mix) (verify with manual).
Length:
Refer to official specifications, generally around 2000 mm.
Width:
Refer to official specifications, generally around 700 mm.
Height:
Refer to official specifications, generally around 1150 mm.
Dry Weight:
Approximately 154 kg (dry weight, consult manual for exact).
Wet Weight:
Approximately 175 kg (wet weight, including fluids, consult manual).
Fuel Capacity:
Approximately 16 liters (including reserve, consult manual).
Front Tire Size:
110/70-17 (typical, verify with manual).
Rear Tire Size:
130/70-17 (typical, verify with manual).
Wheelbase:
Refer to official specifications, generally around 1385 mm.
Safety Standard:
No formal crash ratings for motorcycles of this era; focus on rider-controlled safety.
Braking System:
Dual front disc brakes, single rear disc brake. (Specify caliper type and disc diameter if known, e.g., 2-piston calipers).
Suspension Features:
Anti-dive front forks (e.g., Ternary Suspension System or similar), adjustable rear monoshock.
Lighting:
Halogen headlight, LED or incandescent taillight/indicators (verify with manual).
Instrumentation:
Analog tachometer, speedometer, fuel gauge, coolant temperature gauge, indicator lights for turn signals, high beam, neutral, oil pressure.
Rider Aids:
None (This is a 1985 model; features like ABS, traction control are not applicable).
Connection Features:
N/A (Analog systems typical for the era).
Oil Change Interval:
Typically every 3,000-5,000 km or 6-12 months, but always refer to the manual for specific recommendations.
Chain Maintenance Interval:
Inspect and lubricate every 800-1,000 km, adjust tension as needed.
Spark Plug Replacement Interval:
Typically every 10,000-15,000 km, depending on plug type and condition (verify with manual).
Brake Fluid Type:
DOT 3 or DOT 4 (verify with manual), high-performance racing fluid recommended for spirited riding.
Coolant Capacity:
Refer to manual for exact capacity, typically around 1.5-2.0 liters.
Common Wear Items:
Stator/regulator-rectifier failure, carburetor synchronization issues, worn steering head bearings, worn suspension seals.
Engine Performance Quirks:
Can be prone to cam chain noise if not properly tensioned; carburetor jetting may need adjustment based on altitude and modifications.
Part Number Lookup:
Manual includes detailed diagrams for identifying and ordering genuine Suzuki parts.
Suzuki Legacy:
Suzuki has a long history in motorcycle racing and performance-oriented street bikes, establishing the GSX-R line as a benchmark for sportbikes.
Gsxr Lineage:
The GSXR400 GK71B was an early iteration of Suzuki's groundbreaking GSX-R series, known for its lightweight chassis and potent engines, often developed from racing technology.
Production Period:
The GK71B chassis code typically refers to models produced in the mid-1980s, with the 1985 model being a key year.
