🏷️ Basic Information Identification Make: Kawasaki Model: KX125 / KX250 Model Variant: 2-Stroke Competition Motocross Generation Model Years Covered: 1990-1991 👋 Introduction Market Position Positioning: The Kawasaki KX series of the early 1990s was a dominant force in motocross racing, known for its potent 2-stroke power and agile handling. This manual caters to owners and mechanics looking to maintain, repair, and optimize these competitive machines. Competitive Analysis Competitors: This manual is essential for owners of the 1990-1991 Kawasaki KX125 and KX250, directly competing with Yamaha YZ125/YZ250, Honda CR125R/CR250R, and Suzuki RM125/RM250 models of the same era. Key Features Features: Instant digital access, comprehensive coverage of all major systems, detailed troubleshooting guides, and lifetime protection policy for lost or damaged files. 📋 Manual Details Coverage Areas Regions Covered: Global (specifications may vary by region, but core procedures are universal) Manual Type Type: Repair Manual / Workshop Manual / Owner's Manual / Service Manual Language Language: English Format Format: Digital Downloadable PDF 📖 Manual Coverage Systems Covered Engine: Comprehensive coverage of the 2-stroke engine, including top-end and bottom-end components, power valves, carburetor tuning, and cooling system. Transmission: Detailed instructions for the 6-speed transmission, including gear inspection, shift drum and forks, clutch operation, and gearbox lubrication. Fuel System: In-depth coverage of the fuel tank, fuel lines, fuel petcock, and carburetor (likely Keihin or Mikuni), including jetting specifications and adjustments. Lubrication Cooling: Information on the oil injection system (if applicable for the year/model), gearbox oil, and engine cooling system (liquid-cooled design). Electrical System: Wiring diagrams, ignition system (CDI, spark plug specifications), lighting, and basic electrical troubleshooting. Suspension: Front fork (likely Kayaba or Showa with adjustable compression and rebound) and rear shock absorber (likely with adjustable preload, compression, and rebound) maintenance, service, and tuning. Steering System: Steering head bearing maintenance and adjustment. Bodywork Frame: Fairing removal and installation, seat, fuel tank, and frame inspection. Brakes: Front and rear disc brake systems, including caliper maintenance, brake pad replacement, hydraulic system bleeding, and lever/pedal adjustments. Wheels Tires: Wheel bearing maintenance, spoke tensioning, tire selection and inflation pressure recommendations. Intake Exhaust: Airbox and filter maintenance, exhaust system inspection and service, power valve cleaning and operation. Procedures Included Routine Maintenance: Oil changes, filter cleaning/replacement, chain adjustment, spark plug inspection, general bolt checks. Engine Overhaul: Complete engine disassembly, inspection of internal components (piston, rings, cylinder bore, crankshaft, bearings), reassembly, and torque specifications. Transmission Service: Removal and installation of transmission components, gear meshing checks, and clutch adjustments. Carburetor Tuning: Detailed instructions for disassembling, cleaning, and re-jetting the carburetor for various conditions and modifications. Suspension Servicing: Fork oil changes, seal replacement, shock absorber servicing, and suspension adjustment techniques. Electrical Troubleshooting: Diagnostic procedures for common electrical issues using wiring diagrams. Frame And Chassis Repair: Inspection of frame integrity, steering head bearing replacement, and swingarm bearing service. Technical Depth Depth: Comprehensive, covering everything from basic owner maintenance to full engine rebuilds and advanced troubleshooting. Suitable for both novice mechanics and experienced technicians. 📊 Manual Specifications File Format Format: PDF Searchability: Searchable text for quick information retrieval. Printability: Printable pages for on-site use. Print Quality Resolution: High-resolution scans ensuring clarity of text and diagrams. Binding Type Type: N/A (Digital Download) Paper Type Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Type: Liquid-cooled, 2-stroke, single-cylinder Kx125 Bore X Stroke: 56.0 x 49.2 mm (approximate, may vary slightly) Kx250 Bore X Stroke: 66.0 x 72.0 mm (approximate, may vary slightly) Kx125 Displacement: 124 cc (approximate) Kx250 Displacement: 249 cc (approximate) Power Valves: KIPS (Kawasaki Integrated Power-valve System) for improved low-end and mid-range power delivery. Performance Horsepower Kx125: Estimated 35-40 HP (at crank, stock) Horsepower Kx250: Estimated 45-50 HP (at crank, stock) Fuel System Carburetor Kx125: Keihin PWK35 or similar Carburetor Kx250: Keihin PWK37 or similar Fuel Type: Unleaded gasoline (91 octane or higher recommended) Oil Mixture: Typically 32:1 or 40:1 pre-mix ratio or separate oil injection system, depending on specific sub-model and regional configuration. Lubrication Gearbox Oil Type: SAE 80 or 90 GL-4 hypoid gear oil. Specific part numbers often available in the manual (e.g., Kawasaki Genuine Gear Oil). Cooling System Coolant Type: Mixture of distilled water and ethylene glycol-based antifreeze (typically 50/50). 🔧 Transmission Standard Type: Constant mesh, 6-speed, return shift Features Clutch Type: Wet, multi-disc Drive Type: Chain drive 📐 Dimensions Exterior Dimensions Note: Specific dimensions vary slightly between KX125 and KX250. Manual will contain exact figures. Weights Dry Weight Kx125: Approximately 210-215 lbs (95-98 kg) Dry Weight Kx250: Approximately 225-230 lbs (102-104 kg) Fuel Capacity: Approximately 2.5 - 3.0 gallons (9.5 - 11.3 liters) Wheelbase Note: Specific wheelbase figures will be detailed in the manual. Seat Height Note: Specific seat height figures will be detailed in the manual. 🛡️ Safety Features Ratings Ratings Note: As competition motorcycles, these models are not subject to standard automotive safety ratings (e.g., NHTSA, IIHS). Rider safety relies...