Target Audience:
Owners, mechanics, and enthusiasts of 1990-1991 Kawasaki KX125 and KX250 motocross motorcycles.
Value Proposition:
Provides exhaustive factory-level repair and maintenance information, eliminating the need for multiple or incomplete sources, with no recurring fees.
Features:
Comprehensive coverage, factory data, instant download accessibility, long-term usability (no expiry).
Primary Focus:
Full Service and Repair
Estimated Page Count:
Detailed (Specific count not provided, but implies comprehensive coverage)
Type:
Factory Service Repair Workshop Manual
Format:
Digital Download (Computer, Tablet, Smartphone)
Engine:
Complete overhaul, carburetor tuning, ignition system, cooling system (if applicable, though these are typically air-cooled), lubrication, exhaust system.
Transmission:
Gearbox inspection, clutch service, shift mechanism, maintenance, and repair.
Chassis:
Frame inspection, suspension (front forks, rear shock absorber), steering system, wheel bearings, swingarm maintenance.
Brakes:
Front and rear brake system service (hydraulic/cable), pad replacement, fluid bleeding, caliper maintenance.
Electrical:
Ignition system diagnosis, lighting, wiring diagrams, troubleshooting electrical faults.
Bodywork:
Panel removal/installation, seat, fuel tank, plastics.
Maintenance:
Routine servicing, oil changes, filter replacements, spark plug service, chain adjustment, pre-ride inspections.
Repair:
Engine rebuilds, transmission repairs, suspension overhauls, carburetor rebuilding, electrical diagnostics and repair, brake system repairs.
Troubleshooting:
Diagnostic procedures for common and uncommon issues, symptom-based troubleshooting guides.
Depth:
Comprehensive factory-level detail, suitable for professional mechanics and experienced DIY enthusiasts.
Kx125 Engine Type:
Liquid-cooled, 2-stroke, reed valve induction
Kx250 Engine Type:
Liquid-cooled, 2-stroke, reed valve induction
Kx125 Bore X Stroke:
52.5 mm x 57.7 mm (typical for this era)
Kx250 Bore X Stroke:
68.4 mm x 68.5 mm (typical for this era)
Kx125 Displacement:
123 cm³ (typical for this era)
Kx250 Displacement:
249 cm³ (typical for this era)
Kx125 Horsepower:
Approx. 35-40 HP (estimated for the era)
Kx250 Horsepower:
Approx. 45-50 HP (estimated for the era)
Carburetor Kx125:
Mikuni VM28SS (typical, specific model may vary)
Carburetor Kx250:
Mikuni TM34SS (typical, specific model may vary)
Fuel Type:
Unleaded gasoline (91 octane or higher recommended) mixed with 2-stroke oil
Oil Mix Ratio:
Typically 20:1 or 32:1 (refer to manual for precise ratio and oil specification)
Transmission Type:
6-speed constant mesh, foot-shift
Clutch Type:
Wet, multi-disc, cable-actuated
Transmission Oil Spec:
SAE 10W-30 or 10W-40 API SE classification motorcycle oil (refer to manual for exact specification)
Kx125 Overall Length:
Approx. 2185 mm (typical for this era)
Kx250 Overall Length:
Approx. 2190 mm (typical for this era)
Kx125 Wheelbase:
Approx. 1450 mm (typical for this era)
Kx250 Wheelbase:
Approx. 1455 mm (typical for this era)
Kx125 Dry Weight:
Approx. 90 kg (typical for this era)
Kx250 Dry Weight:
Approx. 97 kg (typical for this era)
Safety Standards:
N/A (Performance off-road vehicles are not typically rated by consumer safety organizations like NHTSA)
Braking System:
Hydraulic disc brakes front and rear.
Suspension Performance:
Advanced long-travel suspension systems designed for off-road terrain absorption and control.
Frame Construction:
Robust steel perimeter frame for durability and rigidity.
Spark Plug Replacement:
Refer to manual for specific hours/miles, typically every 20-40 hours of riding.
Air Filter Cleaning:
After every few rides or as needed based on conditions, detailed cleaning and oiling procedures in manual.
Chain Lubrication And Adjustment:
Frequent checks and lubrication are critical for longevity, adjustment as per manual specifications.
Engine Top End Overhaul:
Recommended every 50-100 hours of hard use, detailed procedures in manual.
Coolant Type:
Ethylene glycol-based coolant with corrosion inhibitors (refer to manual for specific type and ratio).
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid (refer to manual for exact specification).
Power Valve Operation:
Potential for sticking or carbon buildup; requires regular cleaning and lubrication as per manual.
Carburetor Jetting:
Sensitivity to altitude and temperature changes; requires meticulous jetting adjustments for optimal performance.
Suspension Seals:
Wear and tear on fork seals and shock seals are common with off-road use, requiring periodic replacement.
Clutch Wear:
Friction plates can wear over time, especially with aggressive riding; clutch service and adjustment are essential.
Kawasaki Motocross Legacy:
Kawasaki has a long and successful history in motocross racing, with the KX series being a dominant force for decades.
Kx125 Evolution Era:
The 1990-1991 models represent an evolution of the highly competitive 125cc class, focusing on power delivery and handling improvements over previous generations.
Kx250 Evolution Era:
These years mark a significant period for the 250cc class, with Kawasaki refining its potent two-stroke engine and chassis for optimal performance.
Manufacturing Location:
Japan (typical for Kawasaki performance models of this era)
Motocross Performance Awards:
Kawasaki KX models of this era consistently received praise and awards in motocross magazines for their performance and competitiveness.
Magazine Reviews:
Often ranked highly by publications like Motocross Action Magazine and Dirt Rider Magazine for their class-leading power and handling.
Manufacturing Standards:
Manufactured to strict Kawasaki quality and performance standards.
