Market Position:
The Kawasaki KX series is a highly competitive line of motocross bikes, renowned for their performance and agility in the competitive 125cc and 250cc classes. This manual targets owners and technicians who demand precise information for maintaining and repairing these high-performance machines.
Competitive Analysis:
During the 2003-2004 model years, the KX125 and KX250 competed against established models from Yamaha (YZ125/YZ250), Suzuki (RM125/RM250), and Honda (CR125R/CR250R). This manual provides specific data for these Kawasaki models, differentiating it from generic repair guides.
Key Features:
Comprehensive coverage of both 125cc and 250cc models for two consecutive years, detailed technical specifications, step-by-step repair procedures, diagnostic aids, and clear illustrations/diagrams, all presented in German.
Systems Covered:
General Information, Regular Maintenance, Fuel System, Cooling System, Engine Top End, Right Engine Side, Engine Removal/Installation, Engine Bottom End/Transmission, Wheels/Tires, Final Drive, Brakes, Suspension, Steering, Electrical System, Appendix
Estimated Page Count:
High (typical for a comprehensive workshop manual, likely 300+ pages)
Manual Type:
Workshop Manual / Service Manual
Format:
Likely Printed Book or Digital PDF
Engine Systems:
Top end (cylinder, piston, rings, cylinder head), Right engine side (clutch, gearbox input/output shafts, kickstart mechanism), Engine removal/installation, Bottom end (crankshaft, connecting rod, bearings, seals), Transmission (gear selection, ratios, lubrication)
Chassis Systems:
Fuel system (carburetor tuning, fuel lines, tank), Cooling system (radiator, hoses, coolant), Wheels and tires (spoke tension, rim repair, tire mounting, pressure), Brakes (hydraulic system, caliper, master cylinder, pads, discs), Suspension (front forks - damping, springs, seals; rear shock - adjustment, rebuild), Steering (bearings, geometry, controls)
Electrical Systems:
Wiring diagrams, ignition system, lighting, charging system (if applicable for models with lights), troubleshooting electrical faults
Maintenance Procedures:
Regular scheduled maintenance, fluid checks and changes, filter replacement, spark plug inspection/replacement, chain adjustment, brake bleeding
Repair Procedures:
Engine overhaul (top and bottom end), carburetor rebuild, suspension fork service, brake caliper overhaul, wheel bearing replacement, general assembly/disassembly
Troubleshooting:
Diagnostic procedures for common running issues, electrical problems, and mechanical failures
Technical Depth:
Comprehensive (covers routine maintenance to complete engine rebuilds, including detailed specifications and diagrams)
Digital File Format:
Likely PDF, potentially searchable text and image-based scans
Print Quality:
High-resolution scans or professionally printed pages, ensuring clarity of diagrams and text
Binding Type:
For printed manuals: Stapled, perfect bound, or spiral bound for durability in a workshop environment
Paper Type:
For printed manuals: Durable, possibly coated paper to resist grease and oil stains in a workshop setting
Engine Type Kx125:
Liquid-cooled, 2-stroke, single-cylinder, Reed valve induction
Engine Type Kx250:
Liquid-cooled, 2-stroke, single-cylinder, Reed valve induction with KIPS (Kawasaki Integrated Power-valve System)
Bore Stroke Kx125:
54.0 x 54.5 mm
Bore Stroke Kx250:
66.4 x 72.0 mm
Displacement Kx125:
123.7 cc
Displacement Kx250:
249 cc
Compression Ratio Kx125:
9.2:1 (for 2003-2004)
Compression Ratio Kx250:
8.9:1 (for 2003-2004)
Horsepower Kx125:
Approx. 37-39 HP (actual figures vary by year and testing)
Horsepower Kx250:
Approx. 46-48 HP (actual figures vary by year and testing)
Carburetor Kx125:
Keihin PWK38, Single
Carburetor Kx250:
Keihin PWK39, Single
Fuel Type:
Unleaded gasoline, minimum octane rating of 91 (AKI) / 95 (RON)
Fuel Mixture:
Premix: 20:1 ratio (e.g., 20 parts gasoline to 1 part 2-stroke oil) using API TC or JASO FD certified oil
Fuel Tank Capacity Kx125:
8.0 Liters (2.1 US gal)
Fuel Tank Capacity Kx250:
8.0 Liters (2.1 US gal)
Transmission Type:
6-speed constant mesh, sequential manual
Clutch Type:
Wet, multiple-disc, cable operated
Gear Ratios:
Specific gear ratios are detailed within the manual for each model and year.
Transmission Oil Type:
Kawasaki Motorcycle Gear Oil SAE 10W-40 or equivalent API GL-4 or GL-5 rated hypoid gear oil
Transmission Oil Capacity:
Approx. 1.0 Liters (1.1 US qt) - refer to manual for exact specification
Length Kx125:
Approx. 2155 mm (84.8 in)
Length Kx250:
Approx. 2155 mm (84.8 in)
Width Kx125:
Approx. 800 mm (31.5 in)
Width Kx250:
Approx. 800 mm (31.5 in)
Height Kx125:
Approx. 1235 mm (48.6 in)
Height Kx250:
Approx. 1235 mm (48.6 in)
Dry Weight Kx125:
Approx. 91 kg (200.6 lbs)
Dry Weight Kx250:
Approx. 98 kg (216.0 lbs)
Curb Weight:
Not typically published for motocross bikes, but would include fluids and ready-to-ride weight.
Safety Ratings:
Motocross motorcycles are not subject to the same safety rating standards (e.g., NHTSA crash tests) as road-going vehicles. Safety is paramount in the design for rider control and protection from mechanical failure.
Active Safety Features:
Effective braking systems (disc brakes front and rear), responsive suspension, precise steering geometry, lightweight chassis for maneuverability.
Passive Safety Features:
Strong frame construction, protective bodywork (fenders, number plates), handlebar padding.
Infotainment Systems:
N/A - These are competition motocross motorcycles and do not feature infotainment systems.
Driver Assistance Features:
N/A - No electronic driver assistance features are present on these models.
Connectivity Options:
N/A - No connectivity features are present.
Engine Technology Features:
Kawasaki Integrated Power-valve System (KIPS) on KX250 for improved low-to-mid range power delivery and broader powerband. Liquid cooling for consistent engine performance under high loads. Reed valve induction.
Pre Ride Checks:
Tire pressure, chain tension, brake lever feel, fluid levels (coolant, transmission oil), throttle operation, kill switch functionality.
Regular Maintenance Kx125 Kx250:
Air filter cleaning/replacement (after every few rides), spark plug inspection (as needed, more frequently under hard use), chain lubrication/adjustment (every few rides), transmission oil change (intervals vary, typically every 10-20 hours of use), coolant flush (annually or as specified).
Engine Rebuild Intervals:
Top-end rebuilds (piston/rings) typically recommended every 20-40 hours of competitive use. Bottom-end rebuilds are less frequent, dependent on usage and maintenance.
Engine Oil Type:
High-quality 2-stroke premix oil (JASO FD or API TC rated). Kawasaki K-Plaz or similar recommended.
Transmission Oil Grade:
SAE 10W-40 (API GL-4 or GL-5)
Coolant Type:
Permanent type antifreeze, 50/50 mix with distilled water. Kawasaki Coolant or equivalent.
Brake Fluid Type:
DOT 4 hydraulic brake fluid.
Common Issues:
Spark plug fouling (especially if ridden gently or with incorrect jetting), clutch wear, piston/ring wear due to the nature of 2-stroke engines and racing use, suspension seal leaks if maintenance is neglected, potential carburetor jetting sensitivity to altitude and temperature.
Maintenance Impact On Longevity:
Diligent adherence to the maintenance schedule, particularly with air filter care, proper premix ratios, and regular transmission oil changes, is crucial for engine longevity and optimal performance.
Brand Heritage:
Kawasaki has a long and successful history in motocross racing, with the KX line being a cornerstone of their off-road performance for decades. The KX series is synonymous with power and winning pedigrees.
Model Evolution 2003 2004:
The 2003 and 2004 KX models represented a refinement of Kawasaki's successful motocross platform. These years saw chassis updates, engine tuning improvements, and suspension refinements to maintain competitiveness. The KX125 continued to be a strong contender in the highly competitive 125cc class, while the KX250 offered potent power for the 250cc class, often featuring the advanced KIPS power-valve system.
Production Origin:
Japan (Kawasaki Heavy Industries, Motorcycle & Engine Group)
Industry Recognitions:
Kawasaki KX models have historically received numerous positive reviews and accolades from motorcycle publications for their performance, handling, and race-winning capabilities. Specific awards for the 2003-2004 models would be detailed in contemporary road tests and reviews.
Performance Ratings:
Consistently rated as top-tier performers in their respective classes by motocross enthusiasts and professional riders for their power, suspension, and chassis balance.