Category:
Dual-sport / Enduro Motorcycle
Target User:
Enthusiasts, mechanics, owners seeking to maintain or repair their Yamaha WR400F.
Competitors:
KTM EXC series, Honda CRFX series, Suzuki DR-Z series, Kawasaki KDX/KLX series.
Vehicle Focus:
Off-road performance with dual-sport capability.
Manual Value Proposition:
Provides essential technical data and procedures for DIY maintenance and repair, saving on labor costs.
Engine:
Complete overhaul, internal components, cooling system, lubrication system, fuel system, ignition system
Transmission:
Clutch, gearbox, shift mechanism, final drive
Chassis:
Frame, suspension (front and rear), steering, wheels, tires, brakes
Electrical:
Wiring diagrams, lighting, ignition system, charging system, sensors
Bodywork:
Fairings, seat, fuel tank, fenders
Maintenance:
Scheduled maintenance, routine checks, lubrication
Troubleshooting:
Diagnostic procedures, common problems and solutions
Specifications:
Torque values, clearances, fluid capacities, electrical specifications
Type:
Service Repair Manual & Parts Manual
Format:
Digital Download (PDF)
Engine Management:
Carburetor tuning, ignition timing, decompression system
Cooling System:
Radiator, coolant flow, water pump
Lubrication System:
Oil pump, oil filter, oil passages
Fuel System:
Fuel tank, petcock, fuel lines, carburetor (Keihin PD Series)
Ignition System:
CDI unit, spark plug, ignition coil
Transmission And Drivetrain:
Clutch assembly, 5-speed gearbox, chain drive, sprockets
Suspension System:
Front forks (upside-down, adjustable), rear monoshock suspension (adjustable)
Braking System:
Front and rear disc brakes, hydraulic system
Electrical System:
Lighting circuits, horn, kill switch, stator, battery maintenance
Wheels And Tires:
Wheel bearing service, tire pressure recommendations
Routine Maintenance:
Oil changes, filter replacements, chain lubrication and adjustment, spark plug checks, air filter cleaning
Engine Overhaul:
Piston and ring replacement, cylinder inspection, valve clearance adjustment, camshaft replacement, crankshaft inspection
Carburetor Rebuild:
Disassembly, cleaning, reassembly, jetting information
Suspension Service:
Fork seal replacement, fork oil change, rear shock absorber service
Brake System Service:
Brake pad replacement, brake fluid flush and replacement, caliper service
Electrical Troubleshooting:
Using wiring diagrams to diagnose faults, testing components
Wheel And Tire Service:
Tire replacement, spoke tensioning (if applicable), wheel bearing replacement
Depth:
Comprehensive: Covers all aspects from basic maintenance to full engine and chassis rebuilds.
Diagnostic Capability:
High: Detailed troubleshooting guides and symptom-based diagnostics.
Rebuild Procedures:
Complete: Step-by-step instructions for complete disassembly and reassembly of major components.
Engine Type:
4-stroke, Liquid-cooled, DOHC, 5-valve, Single Cylinder
Bore X Stroke:
80.0 mm x 79.6 mm
Compression Ratio:
12.2:1
Carburetor:
Keihin PD42 (42mm) flat-slide carburetor
Horsepower:
Approx. 40-45 HP (claimed, rear wheel)
Torque:
Approx. 35-38 Nm (claimed, rear wheel)
Fuel Type:
Unleaded gasoline (91 octane or higher recommended)
Fuel Tank Capacity:
9.0 Liters (2.4 Gallons)
Fuel Delivery:
Carburetor
Transmission Type:
Constant-mesh, 5-speed
Clutch Type:
Wet, multiple-disc, cable-actuated
Final Drive:
Chain drive, 520 O-ring sealed
Gear Ratios:
1st: 2.571, 2nd: 1.857, 3rd: 1.400, 4th: 1.143, 5th: 0.958
Transmission Fluid:
Yamaha Gear Oil (or equivalent SAE 10W30 API SE classification or higher)
Transmission Fluid Capacity:
1.0 Liters (1.1 US qt)
Engine Oil Change:
Every 10-15 hours of riding or every 6 months.
Air Filter Cleaning:
Every 5-10 hours of riding or as needed in dusty conditions.
Spark Plug Check And Gap:
Every 20-30 hours of riding.
Valve Clearance Check:
Every 30-40 hours of riding.
Chain Lubrication And Adjustment:
Before every ride, adjust tension to 20-30mm free play.
Engine Oil Specification:
Yamalube 4 (10W-40) or equivalent API SG, SH, SJ SE or SF classification motorcycle oil.
Engine Oil Capacity:
1.1 Liters (1.2 US qt) without filter change, 1.2 Liters (1.3 US qt) with filter change.
Coolant Type:
Permanent type antifreeze coolant (50% solution with distilled water)
Brake Fluid Type:
DOT 4 Hydraulic Brake Fluid
Common Wear Items:
Clutch plates, spark plugs, piston rings, valve guides due to high-performance nature.
Carburetor Performance:
Can be sensitive to altitude and temperature changes; requires periodic cleaning and tuning.
Cooling System Efficiency:
Ensure radiator fins are clean and coolant levels are maintained for optimal performance.
Yamaha Motorcycles:
Yamaha Motor Company, Ltd. is a Japanese manufacturer of motorcycles, marine products, and other motorized products. Known for innovation and performance in racing.
Wr400F Development:
Evolved from Yamaha's YZ racing platform, adapting a powerful 4-stroke engine for enduro competition and trail riding.
Manufacturing Location:
Japan
Production Years:
1998-2000 (WR400F), succeeded by WR426F and WR450F.
