Vehicle Segment:
High-performance Off-road Motorcycle (Enduro/Motocross)
Intended Use:
Competitive off-road riding, trail riding, motocross
Key Competitors 2005:
Honda CRF450X, KTM 450 EXC, Suzuki RM-Z450, Kawasaki KX450F
Engine Type Highlight:
Liquid-cooled, DOHC, 4-stroke, single-cylinder
Suspension Technology:
Long-travel, adjustable Kayaba (KYB) suspension
Chassis Design:
Aluminum frame for light weight and rigidity
Engine Mechanical:
Yes (Top end, bottom end, valve train, lubrication, cooling)
Fuel System:
Yes (Carburetor overhaul, fuel lines, fuel tank)
Ignition System:
Yes (CDI, ignition coil, spark plug)
Exhaust System:
Yes (Muffler, header pipe, heat shields)
Transmission And Drivetrain:
Yes (Clutch operation, gearbox, final drive)
Suspension Front:
Yes (Fork disassembly, oil changes, seals, damping adjustments)
Suspension Rear:
Yes (Shock absorber overhaul, linkage maintenance, spring adjustments)
Braking System:
Yes (Hydraulic brake systems, caliper service, master cylinder, fluid replacement, bleeding)
Wheel And Tire:
Yes (Wheel bearing service, tire changes, spoke tension)
Electrical System Components:
Yes (Lighting, horn, battery, starter motor, stator, wiring diagrams)
Frame And Bodywork:
Yes (Frame inspection, seat, plastics, fenders, handlebars)
Routine Maintenance:
Yes (Oil changes, filter replacement, chain adjustment, lubrication)
Engine Rebuild:
Yes (Complete top-end and bottom-end rebuild procedures)
Carburetor Tuning:
Yes (Jetting, float adjustment, cleaning)
Suspension Setup:
Yes (Oil levels, fork pressure, shock adjustments)
Brake Bleeding:
Yes (Front and rear brake systems)
Troubleshooting Fault Finding:
Yes (Diagnostic flowcharts and common issue resolution)
Wiring Diagram Interpretation:
Yes (Color-coded and detailed electrical schematics)
Diagnostic Capabilities:
Advanced (Includes detailed troubleshooting guides and specifications)
Rebuild Level:
Complete (From basic maintenance to full engine and component overhauls)
Special Tools Requirement:
Specified (Lists any necessary special tools for specific procedures)
Engine Displacement:
449 cc (27.4 cu. in.)
Engine Bore X Stroke:
95.0 mm x 63.4 mm (3.74 in x 2.50 in)
Compression Ratio:
12.5:1
Valve Actuation:
DOHC, 4 valves
Horsepower Estimated:
Approximately 45-50 HP (at crank, depending on tuning and specific model variant)
Torque Estimated:
Approximately 30-33 lb-ft (at crank)
Carburetor Type:
Keihin FCR MX39 (flat slide, accelerator pump)
Fuel Type:
Unleaded gasoline, octane rating 91 or higher recommended
Oil Capacity With Filter Change:
1.10 L (1.16 US qt, 0.97 Imp qt)
Coolant Type:
Yamalube High Performance Coolant or equivalent (50/50 mix of antifreeze and distilled water)
Coolant Capacity:
0.85 L (0.89 US qt)
Crash Test Ratings:
N/A (Motorcycle, not subject to automotive crash testing standards)
Braking System Type:
Hydraulic disc brakes (Front and Rear)
Front Brake Specification:
250 mm petal disc
Rear Brake Specification:
245 mm petal disc
Lighting:
Halogen headlight, LED taillight
Engine Oil Change:
Every 20 hours of riding or every 3 months, whichever comes first.
Oil Filter Replacement:
Every engine oil change (recommended).
Air Filter Cleaning:
Every 5-10 hours of riding or as needed based on riding conditions.
Spark Plug Inspection Cleaning:
Every 20 hours of riding.
Valve Clearance Check:
Every 200 hours of riding or annually.
Chain Lubrication Adjustment:
Every 5-10 hours of riding or after washing.
Engine Oil Viscosity:
10W-40
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid.
Carburetor Idling Instability:
Some models may experience occasional idling issues, often resolved by cleaning the carburetor or adjusting the idle screw.
Clutch Lever Play:
Regular adjustment of clutch cable free play is important for smooth operation.
Suspension Seal Wear:
As with many dirt bikes, fork seals can wear over time, especially with aggressive riding. Regular inspection and maintenance are advised.
Yamaha Motorcycles:
Yamaha Motor Company is a Japanese manufacturer of motorcycles, marine products, and other motorized products. Founded in 1955, Yamaha has a long and rich history in motorsports, particularly in road racing and motocross.
Wr450F Timeline:
The WR450F, introduced as a four-stroke alternative to their two-stroke YZ models, evolved significantly. The 2003 model year marked a major redesign with a new aluminum frame and a 450cc engine. The 2005 model continued this successful platform with refinements. Subsequent models introduced fuel injection and other technological advancements.
Manufacturing Origin:
Japan
Motocross Magazine Awards:
The WR450F platform generally received positive reviews and accolades in motocross and off-road publications for its power and handling in its class during its production years.
Overall Performance Rating:
Highly rated for off-road performance and engine power.
Emissions Certification:
Compliant with prevailing emissions standards for off-road vehicles of its time in its intended markets.