The Yamaha WR400F, produced from 2000 to 2008, is a competition-focused four-stroke off-road motorcycle renowned for its potent engine and robust performance in motocross and enduro riding. Building on Yamaha's extensive heritage in off-road racing, the WR400F was engineered with a liquid-cooled 396cc engine, typically producing around 40-45 horsepower, and a 5-speed transmission, optimized for versatile off-road conditions. Its design emphasizes reliability and capability, positioning it as a strong contender against key competitors of its era, such as models from KTM, Honda, Kawasaki, and Suzuki. The motorcycle features hydraulic disc brakes for effective stopping power and a steel semi-double cradle frame for structural integrity, with a seat height around 38 inches and substantial ground clearance for navigating challenging terrain.
This workshop repair service manual provides comprehensive, professional-level diagnostic, repair, and maintenance information for all WR400F models across its production years. It covers a wide array of systems, including the fuel, cooling, engine top end, clutch, lubrication, transmission, wheels, tires, brakes, suspension, steering, frame, and electrical systems. Detailed procedures for service, maintenance, troubleshooting, disassembly, assembly, cleaning, and reinstallation are included, alongside critical specifications, diagnostic information, and wiring diagrams. This manual is an essential resource for DIY mechanics and professional technicians, enabling accurate upkeep and cost-effective repairs, ensuring the optimal performance and longevity of the Yamaha WR400F.
Years Covered:
2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
Engine Code Identifier:
Likely a 4SP designation for 4-stroke, specific engine code not provided but consistent across years for this model line
Chassis Code Identifier:
Specific chassis codes vary by year and region but the manual covers the WR400F platform across this range
Vehicle Type:
Competition Motocross/Enduro Motorcycle
Key Competitors Era:
KTM EXC, Honda CR, Kawasaki KX, Suzuki RM
Manual Value Proposition:
Comprehensive, accurate, and detailed technical information for DIY mechanics and professional technicians, enabling cost savings on repairs and maintenance.
Digital Manual Advantage:
No risk of damage from oil/dirt, ability to print specific sections, instant access
Manual Completeness Assurance:
Guaranteed to be complete and intact, without missing or corrupt parts/pages.
Coverage Scope:
All Models, All Engines, All Trim Types, All Transmission Types
Estimated Page Count:
Hundreds of pages (as stated in product description)
Type:
Workshop Repair Service Manual
Origin Of Manual:
OEM (Original Equipment Manufacturer) equivalent, same manual used in official service/repair shops.
Covered Systems:
General Information, Fuel System, Cooling System, Engine Top End, Clutch, Engine Lubrication System, Engine Removal/Installation, Crankshaft/Transmission, Wheels/Tires, Final Drive, Brakes, Suspension, Steering, Frame, Electrical System, Appendix
Electrical System Detail:
Includes detailed wiring diagrams, troubleshooting for ignition, lighting, and charging systems.
Suspension Details:
Covers front forks (likely upside-down telescopic) and rear monoshock suspension, including adjustment and maintenance.
Brake System Details:
Detailed information on hydraulic brake system components, including fluid replacement, caliper service, and pad replacement.
Wheel Tire Final Drive Details:
Includes information on wheel bearing maintenance, tire pressure, and chain drive adjustment/lubrication.
Included Procedures:
Service, Maintenance, Troubleshooting, Repair, Disassembly, Assembly, Cleaning, Reinstalling Procedures, Diagnostic information, Electrical service procedures, Wiring diagrams
Engine Rebuild Procedures:
Complete procedures for engine top-end rebuild, crankshaft and transmission disassembly/assembly.
Troubleshooting Electrical:
Specific troubleshooting guides for electrical system faults, often integrated with wiring diagrams.
Depth Of Information:
Professional-level diagnostic, repair, and maintenance information as used by local service/repair shops; detailed substeps, critical specifications, critical information (notes, cautions, warnings)
Diagnostic Capabilities:
Comprehensive diagnostics for all major systems, including specific procedures for identifying and resolving faults.
Searchability:
PDF format typically allows for text searching, enhancing usability for finding specific information quickly.
Printability:
Full Printable
Delivery:
Instant Download
Requirements:
Adobe PDF Reader, WinZip
Operating Systems:
All Versions of Windows & Mac
Engine Displacement:
Approximately 396cc (specific bore/stroke not provided, but characteristic of WR400F)
Engine Bore Stroke Typical:
Typical bore around 84mm and stroke around 70mm for this displacement.
Horsepower Estimated:
Likely in the 40-45 HP range (typical for this class and era)
Torque Estimated:
Not specified, but optimized for off-road usability
Fuel Delivery:
Carbureted (likely Mikuni VM series, specific model not provided)
Carburetor Considerations:
Manual likely details specific carburetor tuning, jetting, and cleaning procedures.
Cooling Method:
Liquid-Cooled
Transmission Type:
5-speed constant mesh
Optional Transmissions:
N/A (standard for this model)
Clutch Type:
Wet, multi-plate
Wheelbase:
Varies slightly by year, typically around 1475-1485 mm (58.1-58.5 inches)
Ground Clearance:
Typically around 330-345 mm (13-13.6 inches)
Seat Height:
Approximately 960-970 mm (37.8-38.2 inches)
Dry Weight:
Approximately 115-117 kg (253-258 lbs)
Wet Weight:
Not specified, but includes fluids
Safety Ratings:
N/A (Motorcycles typically do not have NHTSA/Euro NCAP ratings)
Braking System:
Hydraulic disc brakes front and rear
Frame Construction:
Steel semi-double cradle frame
Infotainment Features:
N/A (Competition off-road motorcycle, no infotainment systems)
Rider Assistance:
Focus on mechanical systems for performance and reliability. No electronic rider aids beyond basic ignition and lighting.
Connectivity Features:
N/A
Oil Change Interval:
Refer to manual for specific mileage/hour recommendations (typically every 10-20 hours of use or 1000-2000 miles for severe off-road use)
Air Filter Cleaning:
Frequent cleaning/replacement recommended, especially in dusty conditions (refer to manual)
Engine Oil Type:
Yamalube (or equivalent SAE 10W-40 API SG or higher, JASO MA rated motorcycle oil)
Coolant Type:
Permanent type antifreeze (ethylene glycol base) with distilled water (50/50 mix)
Transmission Oil Type:
Yamalube (or equivalent SAE 75W API GL-4 or GL-5 gear oil, depending on specific gearbox design)
Common Wear Items:
Clutch wear, spark plug fouling, air filter degradation, potential carburetor jetting issues, valve clearance adjustments
Troubleshooting Focus:
The manual's troubleshooting section is crucial for addressing performance issues, starting problems, and electrical gremlins.
Carburetor Maintenance Focus:
The manual's detail on the fuel system is critical for addressing performance tuning and maintenance of the carburetor.
Yamaha Offroad Legacy:
Yamaha has a long and successful history in off-road racing and motocross, dating back to the YZ series. The WR line continues this heritage with features optimized for enduro riding.
Wr400F Development:
The WR400F was introduced as a competition enduro model, evolving from Yamaha's motocross technology. It featured a potent four-stroke engine designed for broad power delivery suitable for various off-road conditions.
Wr400F Market Segment:
Positioned as a competitive off-road machine, bridging the gap between motocross-specific models and street-legal dual-sports.
Production Period:
The WR400F was produced for a significant period, with this manual covering a substantial generational update from 2000 to 2008.
