Yamaha YZ250X / YZ250W / YZ250 Motorcycle Owner's Service Manual, 2008 edition

Official Yamaha Owner's Service Manual for 2008 YZ250X, YZ250W, and YZ250

Master the legendary 2-stroke power of your 2008 Yamaha YZ-series motorcycle! This comprehensive Owner's Service Manual is the definitive technical resource for owners, mechanics, and racers who demand factory-level precision. Whether you are prepping for a weekend at the track or performing a complete engine rebuild, this manual provides the exact specifications and step-by-step procedures used by professional Yamaha technicians.

Designed for the high-performance 249cc liquid-cooled 2-stroke engine, this guide ensures your machine stays in peak competition condition.

Comprehensive Model & Identification Coverage

This manual is specifically tailored for the 2008 model year, covering multiple regional variations of the YZ250 platform:

• YZ250X (2008)
• YZ250W (2008) – Regional designation for USA, Canada, Australia, and New Zealand.
• YZ250 (2008) – Regional designation for Europe and South Africa.

Precise Machine Identification: To ensure you are ordering the correct parts and following the right specs, use the identification locations provided in the manual:

• Vehicle Identification Number (VIN): Stamped on the right side of the steering head pipe.
• Engine Serial Number: Stamped on the elevated part of the right side of the engine cases.
• Model Code Numbers: 1P8D (USA/Canada), 1P8E (Europe), and 1P8G (Australia/New Zealand/South Africa).

Technical Highlights & Professional Features

• Complete Engine & YPVS Mastery: Detailed sections on the Yamaha Power Valve System (YPVS) governor and valves, including specific maintenance for the 66.4 x 72 mm bore and stroke engine.
• Pro-Level Suspension Tuning: Extensive "Tuning" chapter covering both the front telescopic forks (Suspension Oil S1) and the link-type Monocross rear shock (gas/oil damper) to match your riding style and track conditions.
• Keihin PWK38S Carburetor Calibration: Specific jetting specifications (Main Jet #178/#180, Pilot Jet #50/#52) and float height adjustments (5.5–7.5 mm) for different regions.
• Rigorous Maintenance Schedules: Includes the "Every Race" and "Every Fifth Race" inspection intervals for critical components like the piston, rings, and clutch system.
• Factory Torque Specifications: No more guessing—access the exact Newton-meter and Foot-pound values for everything from the cylinder head nuts (25 Nm / 18 ft-lb) to the rear wheel axle (125 Nm / 90 ft-lb).

Detailed Manual Structure:

1. General Information: Machine ID, special tools (Crankcase separating tool, Flywheel puller), and basic control functions.
2. Specifications: Detailed maintenance limits, tightening torques, and cable routing diagrams.
3. Regular Inspection and Adjustments: Pre-operation checks, engine idling, and drive chain slack (48–58 mm).
4. Engine: Disassembly and repair for the cylinder, piston, clutch, water pump, and transmission.
5. Chassis: Front and rear wheel service, brake system bleeding (DOT #4), and steering head maintenance.
6. Electrical: CDI Magneto inspection, ignition timing (0.18 mm B.T.D.C.), and solenoid valve system diagnostics.
7. Tuning: Specialized settings for the engine and chassis to optimize race performance.

Technical Reference Data:

• Spark Plug: NGK BR8EG (0.5–0.6 mm gap)
• Fuel: Premium unleaded (95 octane or higher) mixed at 30:1 with Yamalube 2-R.
• Transmission Oil: Yamalube 4 (10W-30) or SAE 10W-30 type SE motor oil.

Invest in the factory knowledge required to keep your Yamaha at the front of the pack. Get the official 2008 YZ250X Service Manual and maintain your edge on the competition!