Product Category:
Competition Off-Road Motorcycle
Target Audience:
Motocross racers, off-road enthusiasts, and owners performing their own maintenance and repairs.
Competitors At Time:
Honda CR125R/CR250R, Yamaha YZ125/YZ250, Suzuki RM125/RM250, KTM 125 EXC/250 EXC.
Manual Strengths:
Easy-to-read text sections, top-quality diagrams, step-by-step instructions, and highly detailed exploded pictures.
Value Proposition:
Enables correct and efficient completion of any repair or overhaul, saving time and money on dealership service.
Engine Overhaul:
Complete engine disassembly, inspection, repair, and reassembly procedures for both KX125 and KX250 models.
Transmission Service:
Detailed instructions for clutch, gearbox, shift mechanism, and final drive maintenance and repair.
Suspension Systems:
Front fork (conventional/upside-down depending on specific model variant within the range) and rear shock absorber maintenance, seal replacement, oil changes, and valving adjustments.
Braking System:
Front and rear brake caliper, master cylinder, brake line maintenance, pad replacement, bleeding procedures, and rotor service.
Fuel System:
Carburetor disassembly, cleaning, adjustment (jetting), fuel tank, petcock, and fuel line service.
Cooling System:
Radiator inspection, coolant replacement, hose service, and water pump maintenance.
Electrical System:
Ignition system (CDI, spark plug, coil), lighting, charging system (if applicable for specific variants), and wiring diagrams.
Frame And Bodywork:
Chassis inspection, steering head bearing service, swingarm pivot maintenance, plastics removal/installation, and seat servicing.
Routine Maintenance:
Oil changes, filter replacements, chain adjustment, spark plug checks, air filter cleaning, and general inspections.
Troubleshooting Guides:
Diagnostic procedures for common performance issues, starting problems, and component failures.
Engine Rebuild:
Piston replacement, ring installation, cylinder honing or replating, crankshaft inspection, bearing replacement, and gasket sealing.
Suspension Rebuild:
Fork seal and bushing replacement, shock absorber seal head replacement, and complete shock absorber overhauls.
Carburetor Tuning:
Step-by-step instructions for adjusting mixture screws, idle speed, and performing jetting changes for different altitudes and conditions.
Wiring Diagram Interpretation:
Detailed schematics for diagnosing electrical issues and component tracing.
Depth Level:
Comprehensive, suitable for both amateur mechanics and professional technicians. Covers from basic maintenance to complete engine and chassis overhauls.
Kx125 Engine Type:
Liquid-cooled, 2-stroke, single-cylinder
Kx125 Bore X Stroke:
54.0 x 54.5 mm
Kx125 Displacement:
124 cm³ (7.6 cu in)
Kx250 Engine Type:
Liquid-cooled, 2-stroke, single-cylinder
Kx250 Bore X Stroke:
66.4 x 72.0 mm
Kx250 Displacement:
249 cm³ (15.2 cu in)
Kx125 Horsepower Approx:
Approx. 39-40 HP (at crankshaft)
Kx250 Horsepower Approx:
Approx. 47-50 HP (at crankshaft)
Carburetor Kx125:
Keihin PWK35 (typical, may vary slightly)
Carburetor Kx250:
Keihin PWK38 (typical, may vary slightly)
Fuel Requirement:
High-octane unleaded gasoline, mixed with 2-stroke oil (specified ratio, e.g., 32:1 or 40:1).
Kx125 Transmission Type:
6-speed constant mesh, return shift
Kx250 Transmission Type:
6-speed constant mesh, return shift
Clutch Type:
Wet, multiple-disc, manual operation
Final Drive:
D.I.D. 520 VX series chain (typical)
Oil Change Frequency:
Recommended every 10-15 hours of riding, or as per manual for specific conditions.
Air Filter Cleaning:
Recommended after every few rides, or immediately if contaminated.
Chain Maintenance:
Lubricate and adjust chain tension every 5-10 hours of riding, or as needed.
Top End Rebuild Kx125:
Recommended at 30-50 hours of hard riding for optimal performance.
Top End Rebuild Kx250:
Recommended at 40-60 hours of hard riding for optimal performance.
Engine Oil Type Transmission:
Kawasaki's recommended 2-stroke oil for premix, or specific gearbox oil (e.g., SAE 80 or 90 for transmission).
Fork Oil Type:
Kawasaki KHL15-10 (or equivalent SAE 10W suspension fluid)
Coolant Type:
Permanent type antifreeze coolant (e.g., 50/50 mixture of ethylene glycol and distilled water).
Common Wear Items:
Clutch plates, piston rings, spark plugs, chain and sprockets, suspension seals, and wheel bearings.
Carburetor Jetting Sensitivity:
These models can be sensitive to altitude and temperature changes, requiring periodic jetting adjustments for optimal performance.
Clutch Slippage:
Can occur with heavy use or worn clutch plates.
Kawasaki Motorcycle Division Founding:
Established in 1949 as a motorcycle manufacturer.
Kx Series Legacy:
The KX line has a long and successful history in professional motocross and supercross racing, known for its performance and rider-focused design.
Kx125 Kx250 1999 2002 Era:
This generation of KX models represented a significant evolution in chassis design, suspension technology (e.g., Showa inverted forks), and engine performance optimization, competing at the forefront of their respective classes.
Manufacturing Location:
Japan (primary)
Kx Series Racing Success:
Kawasaki KX models have a storied history of championships in AMA Motocross, Supercross, and FIM World Motocross Grand Prix.
Magazine Evaluations Era:
Models from this era were consistently praised in motorcycle publications for their competitive power, advanced suspension, and agile handling.
