Motorcycle Segment:
Middleweight Naked Sportbike / Standard Motorcycle
Target Audience:
Riders seeking a versatile, sporty, and relatively affordable motorcycle for commuting and spirited riding.
Key Competitors:
Yamaha XJ600 Diversion, Kawasaki Zephyr 400, Honda CB400 Four
Engine Type:
Inline-four cylinder, liquid-cooled, DOHC
Design Philosophy:
A balance of performance, comfort, and usability, with a distinctive aggressive styling for its era.
Engine Mechanical:
Complete engine overhaul, cylinder head, pistons, crankshaft, camshafts, valve timing, lubrication system
Fuel System:
Carburetor assembly, cleaning, adjustment, fuel pump, fuel filter, fuel tank
Ignition System:
Ignition timing, spark plugs, coils, CDI unit, wiring diagrams
Cooling System:
Radiator, cooling fan, coolant flow, thermostat, water pump
Exhaust System:
Exhaust pipes, muffler, catalytic converter (if applicable)
Transmission Clutch:
Clutch operation, clutch plates, transmission gears, shift mechanism, lubrication
Drivetrain:
Chain drive, sprockets, rear wheel hub
Brakes:
Front and rear brake systems, calipers, master cylinders, brake pads, brake fluid, bleeding procedures
Suspension:
Front forks (telescopic, cartridge type), rear shock absorber, swingarm, linkage (if applicable)
Steering:
Handlebars, steering head bearings, steering linkage
Electrical System:
Battery, charging system (alternator/stator, regulator/rectifier), lighting, horn, starter motor, wiring diagrams for all circuits
Frame Bodywork:
Frame inspection, fairings, seat, fuel tank, fenders, removal and installation procedures
Routine Maintenance:
Oil changes, filter replacement, spark plug inspection/replacement, chain adjustment, brake fluid checks, tire pressure checks
Troubleshooting:
Diagnostic charts for common starting, running, and electrical issues
Disassembly Assembly:
Step-by-step instructions for component removal and reinstallation
Overhaul Rebuild:
Detailed procedures for engine, transmission, and suspension component rebuilding
Adjustments:
Carburetor synchronization, valve clearance adjustment, clutch and throttle cable adjustment
Torque Specifications:
Essential torque values for all critical fasteners
Wiring Diagrams:
Comprehensive electrical schematics for all vehicle systems
Depth Level:
Comprehensive: Covers basic maintenance to full engine and transmission rebuilds. Suitable for DIY mechanics and professional technicians.
Engine Type:
Liquid-cooled, four-stroke, DOHC, inline-four cylinder
Bore X Stroke:
56.0 mm x 40.4 mm (typical for this engine)
Compression Ratio:
11.5:1 (typical for this engine)
Valve Configuration:
DOHC, 4 valves per cylinder
Horsepower:
Approx. 53-57 PS (39-42 kW) at 11,500 rpm (specifications vary slightly by market and tuning)
Torque:
Approx. 37 Nm (27 lb-ft) at 9,500 rpm (specifications vary slightly by market and tuning)
Fuel Delivery:
Carburetor (Mikuni BDST34, 4x 34mm constant-velocity carburetors)
Fuel Tank Capacity:
15 Liters (approx.)
Oil Type Capacity:
API SE/SF/SG, SAE 10W-40 or 20W-50 (check manual for exact specs), approx. 3.4 L with filter change
Oil Change Interval:
Every 4,000 km or 6 months, whichever comes first (refer to manual for precise recommendation)
Valve Clearance Check:
Every 8,000 km or 12 months (critical for inline-fours)
Spark Plug Replacement:
Every 12,000 km or 12 months
Chain Lubrication Adjustment:
Every 1,000 km or after riding in wet conditions
Engine Oil Viscosity:
10W-40 or 20W-50 (API SE/SF/SG rated)
Coolant Type:
Ethylene glycol based, 50/50 mix with distilled water
Carburetor Issues:
Diaphragm degradation over time, leading to rough idling or poor throttle response. Requires regular cleaning and synchronization.
Stator Failure:
Common in older Japanese motorcycles; can lead to charging system failure. Symptoms include dead battery, dim lights.
Cam Chain Tensioner:
Can become noisy or fail, leading to a rattling sound from the engine. Replacement is recommended.
Fork Seals:
Leaking fork seals are a common wear item, especially on bikes of this age.
Manufacturer Origins:
Suzuki Motor Corporation, founded in Japan in 1909, known for a wide range of products including motorcycles, automobiles, and marine engines.
Gsf400 Introduction:
The GSF400 Bandit was introduced in 1989 (as the GK75A) in Japan, offering a more affordable and accessible inline-four sportbike option compared to larger displacement models.
Key Design Elements:
Characterized by its liquid-cooled inline-four engine, tubular steel frame, and relatively upright riding position, establishing the 'Bandit' family styling.
Market Availability:
Primarily targeted at the Japanese domestic market (JDM) initially, with limited but significant grey import presence in other regions.
Production Period:
1989 - 1997 (for the GK75A generation, with variants and updates)
Manufacturing Location:
Japan
