🏷️ Basic Information

Make:

Kawasaki

Model:

KX250

Year:

2003

Product Code:

99969-1379-01

👋 Introduction

Segment:

High-performance motocross competition.

Competitors:

Primarily competes against Yamaha YZ250, Honda CR250R, and Suzuki RM250 of the same era.

Performance Focus:

Known for its potent two-stroke engine and competitive chassis dynamics, popular in amateur and professional motocross racing.

📋 Manual Details

Coverage Scope:

Comprehensive service and repair for the 2003 Kawasaki KX250 motocross motorcycle.

Estimated Page Count:

400-500

Type:

Factory Service Repair Manual

Language:

English

Format:

Print

📖 Manual Coverage

Engine:

Detailed disassembly, assembly, inspection, and repair of the 2-stroke engine, including top-end (cylinder, piston, rings, cylinder head), bottom-end (crankshaft, connecting rod, bearings), lubrication system, cooling system (if applicable), and ignition system.

Transmission Drivetrain:

Complete coverage of the transmission system, including clutch operation, gear selection, shift forks, transmission shafts, bearings, and final drive (chain and sprockets).

Fuel System:

Carburetor service, adjustment, and overhaul. Fuel tank inspection and cleaning. Fuel line maintenance.

Ignition Electrical:

Ignition system components (CDI, ignition coil), troubleshooting electrical circuits, lighting system (if applicable), wiring diagrams, battery maintenance.

Suspension:

Front fork (upside-down) disassembly, assembly, oil change, seal replacement, and adjustment. Rear shock absorber service and adjustment. Linkage system maintenance.

Brakes:

Front and rear hydraulic disc brake systems. Master cylinder overhaul, caliper service, pad replacement, fluid bleeding, and line inspection.

Chassis Frame:

Frame inspection and repair. Handlebar and control lever adjustments. Footpeg and pedal maintenance. Seat removal and installation.

Bodywork Cosmetics:

Plastic body panel removal and installation (fenders, shrouds, number plates). Graphics and decal application.

Maintenance:

Routine maintenance checks, lubrication points, air filter cleaning, spark plug replacement, chain adjustment, tire pressure checks.

Troubleshooting:

Systematic diagnostic procedures for common starting, running, and performance issues. Fault finding charts.

Repair Rebuild:

Step-by-step instructions for component disassembly, cleaning, inspection, repair, and reassembly for virtually all mechanical and electrical systems.

Installation Adjustment:

Correct procedures for installing new parts, adjusting controls, suspensions, and engine parameters.

Depth Level:

Factory-level detail, suitable for professional mechanics and experienced DIY enthusiasts. Covers complete engine rebuilds, transmission overhauls, and advanced suspension tuning.

📊 Manual Specifications

Digital Quality:

N/A (assumed print)

Print Standard:

Professional, high-resolution printing on durable paper stock suitable for workshop environments.

Binding Method:

Staple-bound or perfect-bound, designed for lay-flat usability.

Paper Quality:

Heavy-duty, gloss or semi-gloss paper to resist grease and dirt.

⚙️ Engine Specifications

Engine Type:

Liquid-cooled, 2-stroke, single-cylinder

Displacement:

249 cc (15.2 cu in)

Bore X Stroke:

70.0 x 64.0 mm (2.76 x 2.52 in)

Compression Ratio:

8.5:1 (typical for this era, check specific spec)

Valvetrain:

Reed valve induction, KIPS (Kawasaki Integrated Power-valve System)

Horsepower:

Approx. 45-50 HP (estimated, varies with tuning)

Torque:

Approx. 28-30 lb-ft (estimated, varies with tuning)

Carburetor:

Keihin PWK38, 38mm, flat slide

Fuel Type:

Unleaded gasoline, 91 octane or higher recommended.

Fuel Mixture:

50:1 ratio with high-quality 2-stroke oil (e.g., Yamalube 2R, Motul 800).

🔧 Transmission

Transmission Type:

5-speed constant mesh

Clutch Type:

Wet, multi-disc

Gear Ratios:

Specific ratios detailed in manual (e.g., 1st: 2.333, 2nd: 1.727, 3rd: 1.333, 4th: 1.090, 5th: 0.916)

Final Drive:

Sealed O-ring chain, 520 pitch

📐 Dimensions

Overall Length:

Approx. 2155 mm (84.8 in)

Overall Width:

Approx. 810 mm (31.9 in)

Overall Height:

Approx. 1250 mm (49.2 in)

Wheelbase:

Approx. 1470 mm (57.9 in)

Ground Clearance:

Approx. 330 mm (13.0 in)

Seat Height:

Approx. 955 mm (37.6 in)

Dry Weight:

Approx. 93 kg (205 lbs)

Curb Weight:

Not typically specified for motocross bikes, but estimated ~100 kg (220 lbs) with fluids.

Fuel Tank Capacity:

8.0 L (2.1 US gal)

🛡️ Safety Features

Safety Certification:

Not applicable (competition off-road vehicle)

Braking System:

Dual piston front caliper, single piston rear caliper, hydraulic disc brakes front and rear.

Suspension Control:

Adjustable compression and rebound damping on front forks and rear shock absorber.

Frame Construction:

High-tensile steel perimeter frame designed for strength and rigidity.

Handlebars:

Strong aluminum handlebars with protective pad.

💡 Technology Features

Infotainment System:

N/A (competition motocross vehicle)

Electronic Aids:

N/A (focus on rider control and mechanical feedback)

Connectivity Features:

N/A

🔧 Maintenance

Oil Change:

Engine oil (transmission oil): Every 10-15 hours of riding or annually. Fork oil: Every 20-30 hours or annually. Refer to manual for specific recommendations.

Air Filter:

Clean after every few rides, depending on conditions. Replace as needed.

Spark Plug:

Inspect every 10-15 hours, replace as needed. Recommended plug: NGK BR9EG or equivalent.

Chain Adjustment:

Check and adjust chain slack regularly, every few rides. Proper slack: 20-30 mm (0.79-1.18 in) at the midpoint of the lower chain run.

Engine Oil:

API GL-4 or GL-5, SAE 10W-40 motorcycle gear oil (e.g., Kawasaki Genuine Gear Oil, Motul Gear 300).

Fork Oil:

Show Oil SAE 0W or SAE 5W (e.g., Kawasaki KSSO 0W, Motul Factory Line 0.5W). Specific volume per fork leg is crucial and detailed in manual.

Brake Fluid:

DOT 4 hydraulic brake fluid.

Coolant:

Pre-mixed ethylene glycol-based coolant with a 50/50 ratio of antifreeze and distilled water.

Power Valve:

The KIPS power-valve system can accumulate carbon deposits, leading to sticking or reduced performance. Regular cleaning is essential.

Clutch:

Clutch wear is common with aggressive riding. Regular inspection of plates and springs is recommended. Ensure correct clutch free play.

Suspension Seals:

Front fork seals can leak over time and with hard use. Replacement of seals and oil is a common maintenance task.

Carburetor Jetting:

Carburetor jetting can be sensitive to altitude, temperature, and modifications. Proper jetting is critical for optimal performance and engine longevity.

📚 Vehicle History

Kawasaki Offroad:

Kawasaki has a long and successful history in motocross racing, with the KX line being a cornerstone of their performance dirt bike offerings.

Kx250 Development:

The 2003 model represents an evolution of Kawasaki's KX250 platform, featuring refinements to the chassis, suspension, and engine performance to remain competitive.

Manufacturing Location:

Japan

Market Availability:

North America, Europe, and other global markets.

🏆 Awards & Recognition

Motocross Wins:

The KX250 platform has numerous wins and championships across various professional and amateur motocross racing series throughout its production years.