Segment:
High-performance Motocross Motorcycle
Target Audience:
Motocross racers, enthusiasts, and mechanics requiring in-depth maintenance and repair information.
Competitors:
Yamaha YZ250, KTM 250 SX, Suzuki RM250, Honda CR250R
Manual Advantage:
Instant download, accessible on mobile devices for on-the-go repairs, protection against damage compared to paper manuals.
Vehicle Advantage:
The KX250 of this era was known for its potent two-stroke power delivery, capable suspension, and competitive motocross performance.
Primary Coverage:
Repair, Service, Maintenance, Troubleshooting
Secondary Coverage:
Parts lookup assistance implied by description of 'Parts Catalogs'
Estimated Page Count:
Estimated 400-600 pages (typical for comprehensive service manuals of this era)
Type:
Downloadable PDF Repair/Service Manual
Format:
PDF (Portable Document Format)
Engine Mechanical:
Engine removal/installation, top-end rebuild (piston, rings, cylinder, head), bottom-end assembly (crankshaft, bearings, seals), lubrication system, cooling system (radiator, hoses, water pump), intake system (carburetor, airbox, reeds), exhaust system (pipe, silencer).
Fuel System:
Carburetor disassembly, cleaning, adjustment (jetting, float height), fuel lines, fuel tank maintenance.
Transmission Drivetrain:
Transmission disassembly/assembly, gear selection, clutch operation, drive chain and sprocket maintenance, adjustment, and replacement.
Suspension Steering:
Front fork ( KYB SSS or similar generation) disassembly, service, oil change, and adjustment. Rear shock absorber (KYB or similar) service and adjustment. Steering system inspection, bearing service, and adjustment.
Bodywork Frame:
Body panel removal/installation, seat, fuel tank, fenders, plastics. Frame inspection and maintenance.
Electrical System:
Ignition system (CDI, coils, spark plug), lighting (if applicable to off-road models), wiring diagrams, troubleshooting electrical faults, charging system (stator, flywheel).
Brakes:
Front and rear brake system maintenance (pads, rotors, calipers, fluid flush), hydraulic system troubleshooting.
Routine Maintenance:
Pre-ride inspections, oil changes (transmission oil), filter cleaning/replacement, chain lubrication and adjustment, bolt torque checks, spark plug inspection.
Major Repairs:
Engine rebuilds, transmission overhauls, suspension servicing, clutch replacement, carburetor tuning.
Troubleshooting:
Diagnostic procedures for common performance issues, starting problems, and component failures. Includes flowcharts and symptom-based guides.
Depth:
Comprehensive, covering detailed disassembly, assembly, torque specifications, clearances, and diagnostic procedures. Suitable for home mechanics and professional technicians.
Type:
Liquid-cooled, 2-stroke, single-cylinder
Displacement:
249 cc (approximately)
Bore X Stroke:
Typically around 66.4 mm x 72 mm (verify specific year)
Ignition:
Digital CDI (Capacitor Discharge Ignition)
Lubrication:
Premix or Automatic Oil Injection (verify specific model year)
Horsepower Estimated:
Approx. 45-50 HP (at crankshaft, varies by year and tuning)
Torque Estimated:
Approx. 28-30 lb-ft (at crankshaft, varies by year)
Carburetor:
Keihin PWK 38mm (typical for this generation)
Fuel Type:
Unleaded gasoline with appropriate 2-stroke oil mix
Length:
Varies slightly by year, typically around 85.6 inches (2175 mm)
Width:
Varies slightly by year, typically around 32.1 inches (815 mm)
Height:
Varies slightly by year, typically around 49.4 inches (1255 mm)
Dry Weight:
Approx. 212.7 lbs (96.5 kg) - Varies by year
Curb Weight:
Not typically specified for motocross bikes, but would include fluids.
Transmission Oil Change:
Every 10-15 hours of riding, or as specified in the manual. Use high-quality 2-stroke transmission oil.
Air Filter Cleaning:
After every few rides, or more frequently in dusty conditions. Requires specific air filter cleaner and oil.
Spark Plug Replacement:
Inspect regularly, replace every 20-30 hours of riding or as needed based on condition.
Top End Rebuild:
Typically every 30-50 hours of hard riding, depending on usage and maintenance.
Transmission Oil:
API GL-4 or GL-5 gear oil, SAE 10W-30 or 80W (check specific manual for exact viscosity and type, e.g., Kawasaki Genuine Gear Oil).
Coolant:
High-quality ethylene glycol-based coolant with anti-corrosion additives, typically a 50/50 mix with distilled water.
Brake Fluid:
DOT 3 or DOT 4 hydraulic brake fluid (verify specific requirement).
2-Stroke Oil:
High-quality synthetic or semi-synthetic 2-stroke racing oil, mixed with gasoline at the manufacturer's specified ratio (e.g., 40:1, 50:1).
Clutch Wear:
Clutch plates can wear out with aggressive riding, requiring periodic replacement.
Power Valve Maintenance:
The exhaust power valve system requires regular cleaning to prevent carbon buildup, which can affect engine performance.
Carburetor Tuning:
Carburetor jetting may need to be adjusted for changes in altitude, temperature, or modifications.
Suspension Seals:
Fork and shock seals can degrade over time and require replacement to prevent oil leaks.
Kawasaki Motorsports:
Kawasaki has a long and successful history in motocross and off-road racing, with the KX line being a cornerstone of their performance lineup.
Kx250 Evolution:
The KX250 two-stroke was a dominant force in its class, undergoing continuous refinement in suspension, chassis geometry, and engine performance throughout its production run. This generation (2005-2008) represents a mature iteration of the platform, often featuring advanced suspension technology like Showa's Separate Function front forks (SFF) or KYB's Speed Sensitive System (SSS).
Manufacturing Location:
Japan (typically)
