Category:
Motocross Competition
Target Audience:
Motocross racers, mechanics, and enthusiasts
Competitors:
Honda CRF250R, Kawasaki KX250F, Suzuki RM-Z250, KTM 250 SX-F
Bike Features:
Lightweight chassis, powerful four-stroke engine, renowned KYB SSS front forks
Manual Value:
Essential for proper maintenance and repair to maximize performance and longevity
Primary Coverage:
Complete repair and maintenance for the 2009 Yamaha YZ250F
Secondary Coverage:
Troubleshooting, diagnostics, technical specifications
Type:
Factory Service Manual / Repair Manual
Format:
Digital (Instant Download)
Interactivity:
Clickable Chapters
Engine:
Complete engine tear-down, rebuild, tuning, lubrication, cooling system
Transmission:
Gearbox inspection, repair, maintenance, lubrication
Chassis:
Frame, swingarm, linkage, bearings inspection and maintenance
Suspension:
Front forks (KYB SSS) and rear shock absorber service, adjustments, seal replacement
Brakes:
Front and rear brake system inspection, fluid replacement, caliper service, master cylinder service
Fuel System:
Carburetor (Keihin FCR) disassembly, cleaning, jetting, fuel tank, fuel pump
Electrical System:
Ignition system, lighting, wiring diagrams, battery, charging system
Cooling System:
Radiator, hoses, coolant replacement
Exhaust System:
Exhaust pipe and silencer maintenance
Wheels And Tires:
Tire pressure, wheel bearing maintenance, spoke tension
Maintenance:
Regular service intervals, fluid changes, filter replacements, chain adjustment
Troubleshooting:
Step-by-step diagnostic procedures for common and uncommon issues
Repair:
Complete disassembly, component replacement, reassembly guidance
Rebuild:
Engine rebuild, including top-end and bottom-end procedures
Adjustments:
Carburetor tuning, suspension adjustments, clutch and throttle cable adjustments
Depth:
Comprehensive - From basic maintenance to full engine and chassis rebuilds
Illustrations:
Detailed photographs and diagrams for clarity
Data Included:
Torque specifications, clearance measurements, fluid capacities
Engine Type:
Liquid-cooled, four-stroke, DOHC, four-valve
Bore X Stroke:
77.0 mm x 53.6 mm
Compression Ratio:
12.8:1
Horsepower Estimated:
Approximately 38-40 hp (at crankshaft, subject to tuning)
Torque Estimated:
Approximately 20-22 lb-ft (at crankshaft, subject to tuning)
Carburetor:
Keihin FCR41 (flat slide, single)
Fuel Type:
Unleaded gasoline, minimum 91 octane recommended
Oil Type:
Yamaha Yamalube 4 (or equivalent JASO FC, API SG or higher) 10W-40 Motorcycle Oil
Oil Capacity:
1.00 L (1.06 US qt) without filter change; 1.10 L (1.16 US qt) with filter change
Transmission Type:
Constant-mesh, 5-speed
Clutch:
Wet, multiple-disc, cable-actuated
Gear Ratios:
1st: 2.750, 2nd: 2.000, 3rd: 1.571, 4th: 1.333, 5th: 1.167
Final Drive:
O-ring sealed chain, 520 pitch
Transmission Oil Type:
Yamaha Gear Oil 80W (or equivalent API GL-4)
Transmission Oil Capacity:
0.70 L (0.74 US qt)
Safety Rating:
N/A (Competition Motorcycle - Not road legal; no NHTSA/Euro NCAP ratings)
Brakes:
Hydraulic disc brakes front and rear for reliable stopping power
Suspension:
Advanced suspension systems (KYB SSS forks) designed for control and stability in off-road conditions
Construction:
Durable aluminum frame and components designed for off-road abuse
Oil Change:
Every 10-15 hours of riding, or as specified in the manual based on usage intensity.
Air Filter Cleaning:
After every few rides, or as needed based on dusty conditions.
Spark Plug Inspection:
Every 20-30 hours of riding.
Valve Clearance Check:
Every 20-30 hours of riding, or as per manual recommendation.
Coolant:
Yamaha's recommended anti-corrosion coolant, a 50/50 mix of ethylene glycol and deionized water.
Brake Fluid:
DOT 4 hydraulic brake fluid.
Common Wear Items:
Clutch plates, brake pads, chain and sprockets, wheel bearings, fork seals.
Carburetor Jetting:
May require adjustment for optimal performance at different altitudes or temperatures.
Brand Focus:
Yamaha has a long and successful history in motocross and off-road racing, known for innovation and performance.
Yz Lineage:
The YZ line has been a cornerstone of Yamaha's motocross offerings for decades, evolving from two-stroke to four-stroke platforms.
2009 Model Update:
The 2009 YZ250F featured refinements over previous generations, often focusing on chassis dynamics, engine tuning, and suspension components.
Manufacturing Origin:
Japan
Motocross Acclaim:
The YZ250F platform consistently received praise and accolades in motocross reviews for its performance and handling.
Suspension Praise:
The KYB SSS (Speed Sensitive System) front forks, standard on this model, were widely regarded as class-leading.
Emissions:
N/A (Competition Motorcycle - Not designed for road use or emissions certification)
