🏷️ Basic Information

Make:

Yamaha

Model:

YZ250F

Model Variant:

YZ250FX (Implied via description, though primarily focused on YZ250F)

Year:

2008

Engine Type:

4-Stroke

Vin Code Year:

8 (for 2008)

👋 Introduction

Motorcycle Segment:

Competition Motocross / Off-Road

Target Audience:

Motocross racers, off-road enthusiasts, and mechanics specializing in Yamaha YZ models.

Key Competitors 2008:

Honda CRF250R, Kawasaki KX250F, Suzuki RM-Z250

Engine Layout:

Single-cylinder, liquid-cooled, DOHC, 4-valve

Manual Advantage:

Provides in-depth, factory-level information essential for maintaining peak performance and longevity of the YZ250F.

📋 Manual Details

Covered Years:

2008

Covered Models:

YZ250F

Page Count Estimate:

Approximately 300-400 pages (typical for comprehensive service manuals of this era)

Manual Type:

Service Repair Workshop Manual

Language:

English

Format:

Digital (likely PDF based on common online sales)

📖 Manual Coverage

Engine Overhaul:

Complete engine disassembly, inspection, repair, and reassembly procedures for the 4-stroke engine.

Fuel System:

Carburetor tuning, cleaning, jetting, fuel pump, fuel lines, and tank service.

Ignition System:

CDI unit, ignition coil, spark plug, wiring diagrams, and troubleshooting.

Cooling System:

Radiator, hoses, water pump, coolant specifications, and bleeding procedures.

Lubrication System:

Oil pump, oil filter, oil passages, oil change procedures, and oil specifications.

Transmission And Clutch:

Gearbox disassembly, inspection, repair, clutch operation, friction plates, steel plates, and springs.

Suspension Front:

Fork disassembly, seal replacement, oil level and type, spring replacement, damping adjustments.

Suspension Rear:

Monoshock linkage, shock absorber service, spring preload, damping adjustments, and bearing maintenance.

Braking System Front:

Caliper service, piston seal replacement, pad replacement, rotor inspection, brake fluid specifications, and bleeding.

Braking System Rear:

Caliper service, pad replacement, rotor inspection, brake fluid specifications, and bleeding.

Wheel And Tire:

Wheel bearing maintenance, spoke tensioning, tire selection, pressure recommendations, and installation.

Electrical System:

Wiring diagrams, lighting, battery maintenance, stator, rectifier/regulator, and starter system (if applicable).

Frame And Bodywork:

Frame inspection, seat removal, tank removal, fender replacement, and handlebar setup.

Preventive Maintenance:

Regular checks, lubrication points, filter replacement, and fluid changes.

Troubleshooting:

Systematic diagnosis of common problems with step-by-step guides and fault codes (if applicable).

Repair Procedures:

Detailed instructions for disassembling, repairing, and reassembling all major components.

Component Replacement:

Guidance on replacing parts such as brake pads, spark plugs, air filters, and bearings.

Torque Specifications:

Precise torque values for critical fasteners across all systems.

Special Tools:

Identification of required special tools for specific repair procedures.

Depth Of Coverage:

Comprehensive, suitable for professional technicians and experienced DIY enthusiasts.

Diagnostic Capabilities:

Advanced diagnostic procedures for electrical and mechanical issues.

Rebuild Guidance:

Detailed instructions for complete engine and transmission rebuilds.

📊 Manual Specifications

File Format:

PDF (Portable Document Format) is the most common digital format for these manuals, offering searchability and compatibility.

Print Quality:

High-resolution, ensuring clarity of diagrams and text if printed.

Binding Type:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Engine Code:

Likely 4DG (model designation often includes engine series)

Displacement:

249 cc (Cubic Centimeters)

Bore X Stroke:

77.0 mm x 53.6 mm (Standard for this generation)

Compression Ratio:

12.8:1 (Typical for 2008 YZ250F)

Valve Train:

DOHC, 4 valves

Cooling Method:

Liquid-cooled

Horsepower Estimate:

Approximately 40-42 HP (at crankshaft)

Torque Estimate:

Approximately 20-22 lb-ft (at crankshaft)

Carburetor:

Keihin FCR MX37 (37mm flat slide, dual-stage methanol-resistant diaphragm)

Fuel Type:

Unleaded gasoline, octane rating 91 or higher

Oil Type:

Yamalube (or equivalent) 4-stroke motorcycle oil, SAE 10W-40 API SG or higher

Oil Capacity:

1.00 L (1.1 US qt) without filter change, 1.10 L (1.2 US qt) with filter change

🔧 Transmission

Transmission Type:

Constant-mesh, 5-speed

Optional Transmissions:

N/A (Single transmission option for this model)

Clutch Type:

Wet, multi-disc

Final Drive:

O-ring sealed chain

📐 Dimensions

Length:

2140 mm (84.3 in)

Width:

815 mm (32.1 in)

Height:

1270 mm (50.0 in)

Seat Height:

990 mm (39.0 in)

Wheelbase:

1475 mm (58.1 in)

Ground Clearance:

335 mm (13.2 in)

Dry Weight:

99 kg (218 lbs)

Fuel Tank Capacity:

8.0 L (2.1 US gal)

🛡️ Safety Features

Safety Ratings:

N/A (Off-road competition vehicles are not subjected to standard automotive safety crash testing).

Active Safety:

Powerful braking systems, responsive suspension for rider control.

Passive Safety:

Robust chassis construction, durable bodywork.

💡 Technology Features

Infotainment System:

N/A (Competition motocross bike, no infotainment features).

Driver Assistance:

N/A (No electronic rider aids in the modern sense, focus is on mechanical feedback and rider skill).

Connectivity:

N/A (No connectivity features).

Tuning Options:

Manual covers carb jetting, suspension adjustments, and general engine tuning for optimal performance.

🔧 Maintenance

Oil Change Interval:

Every 10-15 hours of riding or every 3 months (whichever comes first), or more frequently under severe racing conditions.

Air Filter Cleaning:

After every few rides, or more often in dusty conditions.

Spark Plug Inspection:

Every 15-20 hours of riding.

Valve Clearance Check:

Every 20-30 hours of riding.

Coolant Type:

Yamaha Coolant (or equivalent) 50/50 mixture of ethylene glycol and deionized water.

Brake Fluid Type:

DOT 4 brake fluid.

Common Wear Items:

Clutch plates, piston rings, valve stem seals, wheel bearings, suspension seals.

Potential Issues 2008 Model:

Some owners reported sensitivity to jetting in different altitudes/temperatures and the need for diligent maintenance of the aluminum frame bearings. The carburetor could be finicky if not kept clean.

📚 Vehicle History

Brand Focus:

Yamaha has a long and successful history in motocross and off-road racing, known for performance and innovation.

Yz250F Introduction:

The YZ250F was introduced as Yamaha's premier 4-stroke motocross bike, rapidly gaining popularity for its potent engine and agile handling.

2008 Model Updates:

The 2008 model saw significant revisions, including an all-new aluminum bilateral beam frame, revised engine internals for improved power delivery, and updated suspension settings.

Manufacturing Location:

Japan (Typical for Yamaha performance motorcycles)

🏆 Awards & Recognition

Motorcycle Press Reviews:

The 2008 YZ250F was generally well-received by motorcycle media for its improved chassis and strong engine performance, often praised for its cornering ability and rider-friendliness compared to its predecessors.

Competitive Wins:

Yamaha YZ models have a long history of winning championships in professional motocross and supercross series worldwide.