Motorcycle Segment:
Competition Motocross / Off-road (Enduro-style)
Key Competitors 2003:
Honda CR250R (2-stroke), Kawasaki KX250 (2-stroke), Suzuki RM250 (2-stroke), KTM 250 EXC. The WR250F competed directly with 4-stroke off-road competition from other manufacturers.
Motorcycle Features:
Four-stroke engine for broader powerband and easier rideability compared to 2-strokes of the era, liquid cooling, robust chassis, focus on off-road performance and durability.
Manual Benefit:
Provides dealer-level technical information, enabling owners to perform maintenance, repairs, and diagnostics effectively, saving money and increasing understanding of their motorcycle.
Engine:
Complete engine disassembly, assembly, inspection, and tuning, including cylinder head, valves, piston, connecting rod, crankshaft, timing system, lubrication system, and cooling system.
Chassis:
Frame, suspension (front forks, rear shock, linkages), steering system (triple clamps, steering stem, bearings), wheels, hubs, spokes, brakes (front and rear calipers, master cylinders, lines, pads), swingarm, and footpegs.
Electrical:
Ignition system (CDI, spark plug, coil), charging system (stator, rectifier/regulator), lighting system (if applicable), battery, wiring diagrams, switches, sensors, and troubleshooting for electrical faults.
Fuel System:
Carburetor (including jetting, float bowl, pilot jet, main jet, mixture screw adjustment), fuel lines, fuel tank, and fuel pump (if applicable).
Transmission And Drivetrain:
Clutch operation, inspection, and adjustment; gearbox inspection and repair; drive chain maintenance and adjustment.
Bodywork And Plastics:
Information on removal, installation, and maintenance of fenders, plastics, seat, fuel tank, and associated hardware.
Maintenance:
Regular inspection, lubrication schedule, oil changes, filter replacements, chain cleaning and lubrication, brake fluid checks, coolant checks, air filter service.
Repair:
Complete engine rebuild, carburetor overhaul, suspension servicing, brake caliper rebuild, wheel bearing replacement, steering head bearing service.
Troubleshooting:
Systematic diagnostic procedures for common problems such as starting issues, no spark, engine performance problems, braking issues, electrical faults.
Tuning:
Carburetor tuning and jetting for various conditions, valve clearance adjustment, ignition timing checks (if adjustable).
Installation Procedures:
Covers installation of various components, from engine parts to suspension and bodywork.
Rebuild Procedures:
Detailed step-by-step instructions for complete engine and major component rebuilds.
Depth Of Coverage:
Comprehensive. Covers from basic user maintenance to full factory-level engine and chassis rebuilds.
Diagrams And Illustrations:
Includes detailed part diagrams, exploded views, and procedural illustrations to aid in understanding and execution of tasks.
Torque Specifications:
Includes detailed torque specifications for all critical fasteners throughout the motorcycle, essential for proper assembly and preventing damage.
Engine Type:
Four-stroke, liquid-cooled, DOHC, 5-valve
Bore X Stroke:
77.0 mm x 53.6 mm
Compression Ratio:
12.5:1
Carburetor Model:
Keihin FCR (Flat CR)
Horsepower Estimated:
Approximately 30-35 HP (at crankshaft, varies with tuning)
Torque Estimated:
Approximately 18-20 lb-ft (at crankshaft, varies with tuning)
Fuel Delivery:
Carburetor
Fuel Type:
Unleaded gasoline (minimum 91 octane recommended)
Oil Type:
SAE 10W-40 motorcycle specific synthetic or mineral oil (per manual recommendation)
Oil Capacity:
1.10 Liters (with filter change)
Engine Oil Change Interval:
Every 20 hours of riding or 1 month (whichever comes first, consult manual for specific conditions).
Air Filter Cleaning:
Every 5-10 hours of riding, or more frequently in dusty conditions.
Valve Clearance Check:
Every 100 hours of riding or 6 months (critical for 4-stroke performance).
Engine Oil Viscosity:
SAE 10W-40
Coolant Type:
High-quality ethylene glycol-based antifreeze mixed 50/50 with distilled water.
Brake Fluid Type:
DOT 4 hydraulic brake fluid.
Common Wear Items:
Clutch plates, piston rings, valve guides, wheel bearings, steering head bearings, fork seals, brake pads, chain and sprockets.
Potential Problem Areas:
Carburetor jetting sensitivity to altitude and temperature, potential for valve seat wear in high-hour engines, cooling system maintenance importance.
