Segment:
Performance Motocross/Off-Road Motorcycle
Target Audience:
Motocross racers, off-road enthusiasts, and Yamaha YZ250 owners requiring detailed repair and maintenance information.
Key Competitors Era:
Honda CR250R, Suzuki RM250, Kawasaki KX250.
Vehicle Reputation:
Renowned for its potent 2-stroke engine, agile handling, and competitive performance in its class.
Manual Value Proposition:
Empowers owners to perform in-depth maintenance and repairs, saving costs and maximizing performance and longevity.
Engine:
Complete engine disassembly, assembly, tuning, troubleshooting, and component specifications for the 2-stroke powerplant.
Cooling System:
Details on radiator, hoses, coolant type, and potential maintenance.
Fuel System:
Carburetor identification, adjustment, cleaning, jetting, and fuel delivery system components.
Ignition System:
CDI unit, spark plug specifications, timing, and troubleshooting.
Transmission:
Gearbox disassembly, assembly, inspection, lubrication, and component data.
Clutch:
Clutch plate specifications, operation, adjustment, and service procedures.
Suspension Front:
Fork disassembly, assembly, oil type, levels, seal replacement, and internal component specifications.
Suspension Rear:
Monoshock linkage disassembly, assembly, shock absorber service, spring rate, and damping adjustments.
Brakes Front:
Hydraulic brake system, caliper, master cylinder, brake fluid type, pad replacement, and bleeding procedures.
Brakes Rear:
Hydraulic brake system, caliper, master cylinder, brake fluid type, pad replacement, and bleeding procedures.
Wheels Tires:
Hub maintenance, spoke tensioning, bearing replacement, and tire pressure recommendations.
Electrical System:
Wiring diagrams, lighting, battery maintenance, and troubleshooting of electrical components.
Frame Bodywork:
Frame inspection, plastic fairing removal/installation, seat, and handlebar components.
Routine Maintenance:
Oil changes, filter cleaning/replacement, spark plug checks, chain adjustments, and general lubrication.
Troubleshooting:
Diagnostic flowcharts and procedures for common mechanical and electrical issues.
Engine Rebuild:
Detailed instructions for top-end and bottom-end engine overhauls, including piston, ring, and crankshaft service.
Suspension Service:
Fork seal replacement, fork oil changes, and rear shock absorber servicing.
Brake System Service:
Brake pad replacement, caliper rebuild, and brake fluid bleeding.
Carburetor Rebuild:
Complete carburetor overhaul and tuning procedures.
Electrical Diagnostics:
Fault finding for lighting, ignition, and charging systems.
Depth:
Comprehensive from basic maintenance to complete engine and chassis rebuilds.
Engine Family:
Yamaha YZ Series 2-Stroke
Configuration:
Single-cylinder, liquid-cooled, 2-stroke
Displacement:
249cc (249 cm³)
Bore X Stroke:
Typically around 68.0 mm x 68.0 mm (specific to the 2000 model, confirm in manual).
Compression Ratio:
Varies, but typically in the range of 8.0:1 to 9.5:1 (check manual for exact spec).
Reed Valve System:
Standard for 2-stroke performance.
Power Valve System:
Yamaha Power Valve System (YPVS) for improved torque and power delivery across the RPM range.
Horsepower:
Estimated 40-45 HP at peak (specific figures will be in the manual).
Torque:
Estimated 25-30 lb-ft (specific figures will be in the manual).
Carburetor Model:
Keihin PWK (typically 38mm for this era).
Fuel Type:
Unleaded gasoline with appropriate octane rating (e.g., 91-93 RON).
Oil Mixture:
Pre-mix of gasoline and 2-stroke engine oil (specific ratio, e.g., 40:1 or 50:1, will be detailed).
Length:
Refer to manual for exact dimensions, typically around 84-86 inches.
Width:
Refer to manual for exact dimensions, typically around 32-33 inches.
Height:
Refer to manual for exact dimensions, typically around 50-51 inches.
Dry Weight:
Approximately 214 lbs (97 kg) (check manual for exact figure).
Curb Weight:
Will include fluids, likely around 230-240 lbs.
Fuel Capacity:
Approximately 2.1 gallons (8.0 liters).
Oil Change:
Every 15-20 hours of operation, or as recommended by Yamaha for specific riding conditions.
Air Filter Cleaning:
Frequent cleaning recommended, especially in dusty conditions (after every few rides).
Spark Plug Inspection:
Regular inspection for fouling and wear, typically every 10-15 hours.
Chain Lubrication Adjustment:
Lubricate before every ride, adjust tension as needed (refer to manual for specific slack).
Suspension Service:
Fork oil change and seal inspection recommended every 20-40 hours of use.
Engine Oil Type 2Stroke:
High-quality 2-stroke premix oil (e.g., Yamalube 2R, Motul 800 2T, or equivalent).
Transmission Oil Type:
Yamaha Gear Oil (or equivalent SAE 80 or 85W API GL-4/GL-5 transmission oil). Check manual for specific viscosity and capacity.
Coolant Type:
Ethylene glycol-based coolant with anti-corrosion additives (typically 50/50 mix with distilled water).
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid (check manual for exact specification).
Power Valve Sticking:
Carbon buildup can cause the YPVS to stick, requiring cleaning. Manual provides disassembly and cleaning procedures.
Clutch Wear:
Clutch plates can wear over time, leading to slipping. Manual details inspection and replacement.
Suspension Seals:
Fork seals are prone to leaks, especially with aggressive riding. Manual guides seal replacement.
Carburetor Jetting:
Requires precise jetting based on altitude and temperature. Manual provides baseline settings and tuning guidance.
Heritage:
Yamaha has a long and storied history in motocross and off-road racing, with the YZ line being a cornerstone of their performance offerings.
Yz250 Evolution:
The YZ250 has undergone numerous updates and redesigns since its inception, consistently evolving with technological advancements in engine design, suspension, and chassis.
2000 Model Updates:
The 2000 model likely featured refinements based on previous years' racing feedback, potentially including suspension tuning, engine mapping, and minor chassis improvements. Specific details are in the manual.
Production Period:
The YZ250 has been in continuous production for many years, with the 2000 model representing a significant iteration.