🏷️ Basic Information

Make:

Suzuki

Model:

LT-Z400

Vehicle Type:

Sport ATV / Quad Bike

Product Type:

Service Manual

Product Code:

Suzuki_LTZ400_2003-2008_Service_Manual_PDF

👋 Introduction

Market Segment:

Sport ATV segment, known for its versatility in recreational riding and competition.

Competitors:

Directly competed with models like the Yamaha Warrior 350, Honda TRX300EX/TRX400EX, and Kawasaki KFX400 (which shared a similar platform).

Performance Orientation:

Designed as a high-performance sport ATV with agile handling and a potent engine.

Design Purpose:

Caters to riders looking for a capable machine for trail riding, recreational off-roading, and some forms of amateur racing.

📋 Manual Details

Years Covered:

2003, 2004, 2005, 2006, 2007, 2008

Estimated Pages:

300+

Type:

Factory Service Manual / Workshop Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Full engine disassembly, inspection, assembly, including top-end (cylinder head, valves, piston) and bottom-end (crankshaft, connecting rod, bearings).

Fuel System:

Carburetor (Mikuni BSR36) tuning, cleaning, rebuilding, fuel pump, fuel filter, fuel tank.

Ignition System:

CDI unit, ignition coil, spark plug specifications, timing.

Cooling System:

Radiator, fan, coolant, thermostat, water pump.

Lubrication System:

Oil pump, oil filter (Suzuki Part No. 16510-05240 or equivalent), oil specifications, oil passages, oil change procedures.

Transmission System:

5-speed sequential gearbox, clutch (hydraulic operation), clutch lever adjustment, clutch plate replacement, gearbox disassembly and assembly, gear ratios.

Drivetrain:

Final drive, O-ring sealed drive chain (DID 520VM or equivalent), sprocket replacement, chain maintenance, torque specifications.

Suspension System:

Front independent double A-arm suspension, rear swingarm, shock absorber adjustment (pre-load, rebound, compression), fork seal replacement, bushing inspection.

Steering System:

Handlebar, steering stem, tie rods, steering knuckle, ball joints, steering post bearing inspection and adjustment.

Braking System:

Front dual hydraulic disc brakes, rear single hydraulic disc brake, brake caliper overhaul, brake pad replacement, brake fluid type (DOT 3 or DOT 4), bleeding procedure.

Electrical System:

Wiring diagrams, battery specifications (YB12AL-A2 or equivalent), charging system (stator, rectifier/regulator), lighting system, starter motor, fuses, troubleshooting guide for electrical faults.

Frame And Bodywork:

Chassis inspection, sub-frame mounting, plastic panel removal and installation, seat, fenders, handlebars, footpegs.

Routine Maintenance:

Oil changes, filter replacements, chain adjustment and lubrication, air filter cleaning/replacement, spark plug checks, brake adjustments.

Diagnostic Troubleshooting:

Step-by-step fault finding for engine performance issues, electrical problems, starting difficulties, braking issues, and suspension related concerns.

Disassembly Reassembly:

Complete procedures for dismantling and reassembling all major components and systems for repair or overhaul.

Component Overhaul:

Detailed instructions for rebuilding the engine, carburetor, transmission, brake calipers, and suspension components.

Adjustment Procedures:

Clutch, throttle, brake levers, suspension settings, carburetor idle speed and mixture adjustments.

Torque Specifications:

All critical fastener torque values for engine, chassis, suspension, and brake components.

Depth:

Comprehensive, covering everything from basic maintenance to complete engine and transmission rebuilds, including detailed electrical diagnostics.

Diagnostic Charts:

Includes detailed diagnostic flowcharts and troubleshooting guides for common issues.

Illustrations Diagrams:

Profusely illustrated with clear, step-by-step diagrams and exploded views for component identification and assembly.

📊 Manual Specifications

Format:

PDF

Quality:

High-resolution, allowing for clear printing of text and images.

Binding:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

Text Search:

Likely searchable text, enabling quick access to specific information.

Coverage Level:

Original Factory Service Manual content, providing authoritative information.

⚙️ Engine Specifications

Engine Type:

Four-stroke, liquid-cooled, DOHC, single-cylinder

Displacement:

398 cc

Bore X Stroke:

90.0 mm x 72.5 mm

Compression Ratio:

11.3:1

Horsepower Est:

Approx. 34-38 HP (at crankshaft, manufacturer dependent)

Torque Est:

Approx. 26-28 lb-ft (at crankshaft, manufacturer dependent)

Carburetor:

Mikuni BSR36 with accelerator pump

Fuel Type:

Unleaded gasoline, minimum 87 octane

Ignition Type:

Electronic ignition (CDI)

Cooling Method:

Liquid-cooled

🔧 Transmission

Transmission Type:

Constant mesh, 5-speed sequential manual

Clutch Type:

Wet, multi-plate, hydraulically operated

Optional Gearbox:

N/A

Drive Type:

Chain drive to rear axle

Reverse:

N/A (Manual indicates no reverse gear)

📐 Dimensions

Length:

71.1 in (1805 mm)

Width:

45.3 in (1150 mm)

Height:

43.1 in (1095 mm)

Wheelbase:

50.4 in (1280 mm)

Ground Clearance:

4.7 in (120 mm) - may vary slightly by source

Dry Weight:

Approx. 388 lbs (176 kg)

Fuel Capacity:

3.2 US gal (12.0 L)

🛡️ Safety Features

Safety Certification:

N/A (ATV standards vary, not automotive crash ratings)

Braking System:

Dual front hydraulic disc brakes, single rear hydraulic disc brake, efficient stopping power.

Throttle Safety:

Thumb throttle with safety return spring.

Handlebar Design:

Wide handlebars for improved control and leverage.

Footpegs:

Wide, non-slip footpegs for secure footing.

💡 Technology Features

Infotainment System:

N/A (Basic sport ATV design, no integrated infotainment features like audio or navigation).

Driver Assistance Features:

N/A

Connectivity Options:

N/A

Engine Control:

Basic CDI ignition system with limited electronic engine management, focusing on mechanical reliability.

🔧 Maintenance

Initial Service:

Recommended at 10-hour or 100-mile interval (check manual for specifics).

Regular Oil Change:

Every 100 hours or 1000 miles (whichever comes first), or more frequently under severe use.

Chain Lubrication:

Every 500 miles or as needed, especially after wet riding.

Air Filter Cleaning:

Every 50 hours or more frequently in dusty conditions.

Engine Oil Type:

SAE 10W-40, API SG or higher, JASO MA certified motorcycle oil.

Engine Oil Capacity:

Approx. 1.8 L (1.9 US qt) without filter change, 2.0 L (2.1 US qt) with filter change.

Coolant Type:

Suzuki Super Long Life Coolant or equivalent (50/50 mixture of ethylene glycol and distilled water).

Brake Fluid Type:

DOT 3 or DOT 4 hydraulic brake fluid.

Common Wear Item:

Clutch wear, especially with aggressive riding; requires periodic adjustment and eventual replacement of plates and springs.

Carburetor Issues:

The BSR36 carburetor, while generally reliable, can sometimes experience tuning issues or require cleaning due to ethanol fuels or debris. Accelerator pump operation is critical for throttle response.

Suspension Maintenance:

Fork seals and bushings are common wear items, requiring periodic inspection and replacement to maintain optimal damping and prevent leaks.

Electrical Connections:

Corrosion in electrical connectors can lead to intermittent issues; the manual's wiring diagrams are crucial for troubleshooting.

📚 Vehicle History

Suzuki Atv History:

Suzuki has a long-standing reputation in the powersports industry, particularly with its pioneering sport ATVs like the LT250R and LT500R, establishing a strong lineage for performance and reliability.

Ltz400 Development:

The LT-Z400 was developed as a direct competitor to the highly successful Yamaha Raptor 660 and was co-developed with Kawasaki, leading to the KFX400. This shared platform allowed for efficient production and shared technology.

Production Period:

The LT-Z400 was produced through multiple generations, with the initial models, including those covered by this manual, defining its success in the early 2000s sport ATV market.

Manufacturing Location:

Primarily manufactured in Japan, leveraging Suzuki's extensive manufacturing expertise.

🏆 Awards & Recognition

Industry Acclaim:

While specific awards for the 2003-2008 LT-Z400 might not be widely published, it was consistently praised for its performance, handling, and value within the sport ATV community and enthusiast reviews of its era.

Performance Reviews:

Generally rated highly for its powerful engine, responsive suspension, and agile handling, making it a popular choice for recreational riders and entry-level racers.