Covered Years:
2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
Segment:
Motocross / Off-Road Competition
Reputation:
Known for its potent two-stroke power, agile handling, and competitive performance in its era.
Competitors:
Honda CR250R, Kawasaki KX250, Suzuki RM250, KTM 250 EXC/SX
Engine Type:
Liquid-cooled, 2-stroke, reed valve inducted, single-cylinder
Suspension Front:
Typically features high-quality cartridge forks (e.g., KYB SSS on later models) with extensive adjustability.
Suspension Rear:
Monoshock system with adjustable rebound, compression, and spring preload.
Engine:
Complete disassembly, assembly, tuning, and troubleshooting of the 2-stroke engine.
Fuel System:
Carburetor tuning, jetting, cleaning, and rebuilding; fuel tank and line maintenance.
Cooling System:
Radiator service, coolant checks, and system bleeding procedures.
Exhaust System:
Pipe and silencer maintenance and replacement.
Transmission:
Clutch service, gearbox disassembly and assembly, gear inspection, and maintenance.
Suspension:
Front fork (KYB SSS or similar) and rear shock absorber (Monoshock) maintenance, seal replacement, fluid changes, and adjustment procedures.
Brakes:
Front and rear brake system inspection, hydraulic fluid bleeding, pad replacement, caliper service, and rotor maintenance.
Electrical System:
Ignition system checks, wiring diagrams, lighting, and component testing.
Chassis And Frame:
Frame inspection, steering head bearing maintenance, and general chassis component checks.
Wheels And Tires:
Spoke tensioning, wheel bearing maintenance, tire installation, and pressure checks.
Bodywork And Plastics:
Fairing removal, installation, and general body component maintenance.
Routine Maintenance:
Oil changes, filter cleaning/replacement, spark plug service, chain lubrication and adjustment, air filter cleaning.
Troubleshooting:
Diagnostic procedures for common engine, electrical, and mechanical issues.
Disassembly And Assembly:
Step-by-step guides for major component removal and installation.
Rebuilding:
Detailed instructions for engine top-end (piston, rings, cylinder) and bottom-end rebuilds.
Tuning:
Carburetor jetting and ignition timing adjustments for optimal performance.
Specifications And Measurements:
Torque values, clearances, tolerances, and fluid capacities for all components.
Depth:
Comprehensive, covering everything from basic rider maintenance to full engine rebuilds and advanced diagnostics.
Quality:
High-resolution, searchable PDF
Printable:
Yes, pages can be printed for workshop use.
Binding:
Not applicable (digital download)
Paper Type:
Not applicable (digital download)
Configuration:
249cc, Liquid-cooled, 2-stroke, Single-cylinder
Bore X Stroke:
Approx. 66.4 mm x 72.0 mm
Compression Ratio:
Typically around 9.3:1 to 9.5:1 (varies slightly by year)
Ignition:
CDI (Capacitor Discharge Ignition)
Lubrication:
Premix (Fuel/Oil) or Autolube system (check specific year's manual)
Horsepower Estimate:
Approx. 45-50 hp (at crankshaft, varies by year and tune)
Torque Estimate:
Approx. 30-35 lb-ft (at crankshaft, varies by year and tune)
Carburetor Type:
Keihin PWK (e.g., PWK38 or similar size)
Fuel Type:
Unleaded gasoline, 91 octane or higher recommended (95 RON)
Length:
Approx. 2175 mm (85.6 in) - Varies slightly by year
Width:
Approx. 825 mm (32.5 in) - Varies slightly by year
Height:
Approx. 1280 mm (50.4 in) - Varies slightly by year
Dry Weight:
Approx. 97 kg (214 lbs) - Varies slightly by year
Fuel Capacity:
Approx. 8.2 L (2.2 US gal)
Wheelbase:
Approx. 1475 mm (58.1 in) - Varies slightly by year
Oil Change Engine:
Per manual: After every few rides or 20-30 operating hours (depending on usage intensity).
Air Filter Cleaning:
Regularly, ideally after each dusty ride or ride session.
Spark Plug Service:
Check and clean/replace as per manual recommendations, typically every 20-40 operating hours.
Chain Maintenance:
Lubricate and adjust chain slack every 5-10 operating hours or as needed.
Engine Oil Type:
2-stroke premix oil (specific brand/type recommended in manual) and transmission oil (e.g., Yamalube XYZ, SAE 10W-40 API SE, SF type or equivalent for transmission).
Coolant Type:
Ethylene glycol-based, anti-rust, permanent type coolant, mixed with distilled water at a 50:50 ratio.
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid.
Common Wear Items:
Piston rings, clutch plates, brake pads, wheel bearings, fork seals, swingarm bearings, steering head bearings.
Carburetor Tuning Sensitivity:
These 2-stroke engines are sensitive to altitude, temperature, and humidity changes, requiring periodic carburetor jetting adjustments for optimal performance.
Power Valve Maintenance:
The automatic power valve system requires periodic cleaning and inspection to ensure proper operation and prevent sticking.
Heritage:
Yamaha has a long and successful history in motocross and off-road racing, with the YZ line being a cornerstone of their performance offerings.
Yz Line Evolution:
The YZ250 has undergone continuous development since its inception, with significant updates to suspension, engine technology (e.g., Power Valve system), and chassis design throughout the years.
2000-2009 Key Changes:
This generation saw advancements in suspension (e.g., the introduction of KYB SSS forks on some models), chassis geometry refinement, engine tuning, and braking system improvements. The YZ250FR variant often indicates specific factory race modifications or components.
Production Location:
Japan
Motocross Awards:
The YZ250 platform has historically been highly regarded and has won numerous magazine shootouts and rider awards within the motocross and off-road communities throughout its production years.
Performance Ratings:
Consistently praised for its potent engine, strong mid-range power, and exceptional handling characteristics.
Certifications:
Not applicable (competition off-road motorcycle)
