Segment:
High-performance off-road/motocross motorcycles.
Target User:
Motocross racers, off-road enthusiasts, and motorcycle mechanics.
Competitors:
Yamaha YZ125/YZ250, Honda CR125R/CR250R, Suzuki RM125/RM250, KTM EXC/SX models.
Manual Value:
Provides factory-level insight into maintenance, repair, and performance tuning for these iconic two-stroke motocross bikes.
Digital Convenience:
Instant download, searchable content, and printability enhance usability for on-the-go or workshop reference.
Replacement Policy:
Free replacement offered by the seller, ensuring long-term access to critical service information.
Primary Coverage:
Comprehensive repair and service for Kawasaki KX125 and KX250 models from 1999-2002.
Secondary Coverage:
Maintenance, troubleshooting, diagnostics, specifications, and rebuild procedures.
Type:
Factory Service Manual / Repair Manual
Digital Features:
Clickable chapters, searchable text, no printing or saving restrictions.
Engine:
Complete engine tear down and rebuild, including cylinder, piston, crankshaft, connecting rod, transmission, clutch, lubrication system, cooling system (radiator, coolant). Specifics on carburetion (main jet, pilot jet, mixture screw, idle adjustment).
Drivetrain:
Clutch operation, transmission gear ratios, gearbox maintenance, drive chain adjustment, rear sprocket replacement, primary reduction gear.
Chassis And Suspension:
Front forks (oil level, seal replacement, damping adjustments), rear shock absorber (rebuild, linkage maintenance), swingarm, steering head bearings, wheel bearings, hubs.
Brakes:
Hydraulic front and rear brake systems, caliper service, master cylinder overhaul, brake fluid replacement, pad inspection and replacement, rotor specifications.
Electrical System:
Ignition system (stator, CDI, spark plug), lighting (if applicable for competition use), wiring diagrams, charging system (magneto), troubleshooting 'no spark' issues.
Fuel System:
Fuel tank maintenance, fuel line inspection, carburetor cleaning and adjustment, fuel pump (if applicable).
Bodywork And Plastics:
Fender removal and installation, seat maintenance, fairing and panel removal for access.
Maintenance:
Scheduled maintenance, oil changes, filter replacements, chain lubrication and adjustment, air filter cleaning, spark plug replacement, coolant flush.
Repair:
Complete engine rebuilds (bore, piston replacement), clutch service, transmission overhaul, suspension service, brake caliper rebuilding, electrical component troubleshooting and replacement.
Troubleshooting:
Diagnosis of common problems like 'no spark', starting issues, power loss, engine noise, clutch slippage, suspension performance problems. Error code interpretation (if applicable to ignition or diagnostic systems).
Depth Level:
Complete overhaul and advanced diagnostic level. Suitable for professional mechanics and experienced DIY enthusiasts.
Documentation Type:
Detailed procedures, step-by-step instructions, torque specifications, component diagrams, electrical schematics.
Engine Type:
Liquid-cooled, 2-stroke, single-cylinder.
Bore Stroke Kx125:
54.0 x 54.5 mm
Bore Stroke Kx250:
66.4 x 72.0 mm
Displacement Kx125:
124 cc
Displacement Kx250:
249 cc
Fuel Induction:
Carburetor (Mikuni VM series typically).
Power Delivery:
Aggressive, high-revving powerband characteristic of 2-stroke motocross engines.
Cooling System:
Liquid-cooled via radiator and fan (fan optional/model dependent).
Fuel Type:
Unleaded gasoline (91 octane or higher recommended).
Fuel Mixture:
2-stroke oil mixed with gasoline (pre-mix or injection).
Carburetor Tuning:
Detailed guidance on jetting (main jet, pilot jet, needle, air screw) for various conditions and modifications.
Oil Change:
Regularly check and change gearbox oil as per manual (e.g., every 10-15 hours of riding).
Air Filter Cleaning:
Clean after every few rides or when visibly dirty, especially in dusty conditions.
Spark Plug Replacement:
Check and replace as needed, typically every 20-30 hours of riding or as performance dictates.
Piston Ring Inspection:
Recommended inspection or replacement every 50-75 hours of hard use, depending on engine condition.
Top End Rebuild:
Piston and cylinder inspection/rebuild typically recommended every 75-100 hours for optimal performance, or sooner if signs of wear are present.
Engine Oil Grade:
Refer to manual for specific gearbox oil (e.g., SAE 10W-30, SAE 10W-40 API SG or higher).
Coolant Type:
Permanent type coolant (ethylene glycol based) mixed with distilled water.
Brake Fluid Type:
DOT 4 hydraulic brake fluid.
Fork Oil Type:
Specific fork oil viscosity (e.g., Showa SS-09, Kayaba KSH-09) as per manual, along with specific oil level.
Common Wear Items:
Clutch plates, piston rings, spark plugs, chain and sprockets, wheel bearings, fork seals.
Performance Tuning:
Power valve operation and adjustment, carburetor jetting for altitude and temperature changes are critical for optimal performance.
Carburetor Issues:
Clogged jets, float bowl issues, air leak around the intake boot can cause poor running.
Kawasaki Motocross:
Kawasaki has a long and storied history in motocross, with the KX line being a dominant force in racing for decades.
Kx125 Evolution:
The KX125 went through significant updates during this period, focusing on chassis improvements, engine tuning, and suspension advancements to remain competitive.
Kx250 Evolution:
The KX250 also saw continuous development, with Kawasaki aiming to improve its already strong performance characteristics, particularly in handling and power delivery.
Production Era:
This generation of KX models represents a key period of refinement for Kawasaki's 125cc and 250cc two-stroke offerings.
