Segment:
High-performance motocross motorcycle
Key Competitors:
Yamaha YZ250F, Honda CRF250R, KTM 250 SX-F
Vehicle Focus:
Competition-bred, powerful four-stroke engine, advanced suspension
Manual Benefit:
Enables owners and technicians to perform all necessary maintenance and repairs to keep the KX250F in optimal condition
Engine:
Complete engine assembly, disassembly, inspection, and repair
Fuel System:
Carburetor (including pilot jet, main jet, mixture screw adjustments), fuel pump, fuel tank
Ignition System:
Stator, magneto, coil, spark plug, ignition timing
Transmission:
Clutch, primary reduction gear, gearbox, gearshift mechanism
Cooling System:
Radiator, coolant, hoses, water pump
Suspension:
Front forks (including oil viscosity, level, seals), rear shock absorber, linkage system, swingarm
Brakes:
Front and rear brake systems, caliper, master cylinder, brake pads, brake fluid specifications
Electrical System:
Wiring diagrams, battery, charging system (rectifier, regulator), lights, switches
Chassis And Bodywork:
Frame, handlebars, triple trees, plastics, seat, fenders, exhaust system, muffler
Maintenance:
Scheduled maintenance, fluid changes, filter replacements, lubrication
Troubleshooting:
Diagnosis of common problems, error codes, 'no spark' issues, starting problems
Repair:
Detailed step-by-step instructions for engine, transmission, suspension, brakes, and electrical components
Rebuild:
Complete engine and component rebuild procedures
Installation:
Installation of various parts and components
Torque Specs:
Detailed torque specifications for all fasteners and critical components.
Troubleshooting Guide:
Comprehensive troubleshooting guide for various operational issues.
Depth:
Comprehensive, covering all aspects from basic maintenance to full engine rebuilds
Visuals:
Includes pictures and part diagrams
Part Diagrams:
Includes detailed part diagrams for easy identification and ordering.
Configuration:
Single-cylinder, liquid-cooled, DOHC, four-valve
Bore X Stroke:
77.0 x 53.5 mm
Compression Ratio:
12.5:1
Valve Clearance Intake:
0.04 – 0.08 mm (cold)
Valve Clearance Exhaust:
0.06 – 0.10 mm (cold)
Engine Oil Type:
SAE 10W-40, API SG or higher (specific viscosity depends on ambient temperature, consult manual for precise chart)
Horsepower:
Approx. 36-38 HP (at crankshaft, specific figure may vary)
Torque:
Approx. 24-25 Nm (at crankshaft, specific figure may vary)
Cylinder Material:
Aluminum alloy with plated bore
Carburetor Model:
Keihin FCR37 (flat-slide, four-stroke racing carburetor)
Fuel Type:
Unleaded gasoline (minimum 91 octane recommended)
Fuel Pump Type:
Electric diaphragm pump
Pilot Jet Size:
Consult manual for specific size and adjustment procedure.
Main Jet Size:
Consult manual for specific size and adjustment procedure.
Mixture Screw Turns:
Consult manual for factory setting and adjustment procedure.
Oil Change:
Every 10-15 hours of riding, or annually. Consult manual for specific recommendations based on riding conditions.
Air Filter Cleaning:
Regularly, especially after dusty rides. Consult manual for detailed procedure.
Valve Adjustment:
As per manual schedule, typically every 20-30 hours or annually, depending on use.
Spark Plug Replacement:
As recommended by service manual, typically every 20-40 hours or based on inspection.
Chain Lubrication And Adjustment:
Regularly, based on riding conditions.
Engine Oil Capacity With Filter:
1.0 Liters
Coolant Type:
High-quality ethylene glycol-based coolant with corrosion inhibitors, mixed 50/50 with distilled water.
Fork Oil Viscosity:
Refer to manual, typically SAE 0W or 5W depending on desired damping characteristics.
Fork Oil Level:
Refer to manual for exact measurement (e.g., 100mm from top of inner tube with spring removed).
Common Problems:
While generally reliable, typical motocross maintenance concerns apply: carburetor tuning, suspension wear, clutch wear, and engine wear due to hard use. Specific issues might include jetting with altitude/temperature changes, fork seal leaks.
