Segment:
Entry-level to mid-range utility ATV
Target Audience:
Recreational riders, light agricultural use, trail riding
Competitors Era:
Honda TRX300/300FW, Kawasaki Bayou 300, Suzuki LT-F250/300F, Polaris Sportsman 400
Engine Type:
Reliable air-cooled 4-stroke single-cylinder engine
Drivetrain:
Available in 2WD and 4WD configurations, offering versatility
Suspension:
Independent front suspension (likely), swingarm rear suspension
Transmission:
Automatic (CVT-like or torque converter) transmission with reverse
Primary Coverage:
Comprehensive service and repair information for Yamaha Timberwolf YFB250 ATVs
Scope:
Detailed mechanical, electrical, and bodywork repair and maintenance
Estimated Page Count:
Typically 300-500 pages for a complete service manual of this era
Type:
Service Repair Workshop Manual
Language:
English (assumed, standard for this market)
Engine:
Engine overhaul, disassembly, assembly, tuning, lubrication, cooling system, fuel system, exhaust system
Transmission:
Clutch, gearbox, drive shafts, differentials (for 4WD models), final drive
Chassis:
Frame, suspension (front and rear), steering system, wheels, tires
Brakes:
Brake system diagnosis, repair, fluid replacement, caliper and master cylinder servicing
Electrical:
Ignition system, lighting, starting system, charging system, battery, wiring diagrams, troubleshooting electrical faults
Bodywork:
Body panel removal and installation, fenders, seat, handle bars
Maintenance:
Scheduled maintenance, oil changes, filter replacements, spark plug checks, valve adjustments, lubrication points
Troubleshooting:
Diagnostic procedures for common problems, fault finding guides, diagnostic charts
Repair:
Step-by-step repair instructions for all major components and systems
Rebuilds:
Complete engine rebuild procedures, gearbox overhauls
Specifications:
Torque specifications, clearances, fluid capacities, electrical values
Depth:
Expert level, covering from routine maintenance to complete engine and transmission overhauls
Detail Level:
Includes detailed diagrams, exploded views, and specific step-by-step instructions
Type:
Air-cooled, 4-stroke, SOHC, single-cylinder
Displacement:
Approximately 230cc (229cc is commonly cited)
Bore X Stroke:
Specifics vary by exact model year, but typical for this displacement
Compression Ratio:
Specifics vary by exact model year, but typically around 9.0:1 to 10.0:1
Valve Configuration:
SOHC (Single Overhead Camshaft), 2 valves per cylinder
Horsepower Estimated:
Approximately 15-18 HP (at crankshaft)
Torque Estimated:
Approximately 13-15 lb-ft (at crankshaft)
Carburetor:
Mikuni VM Series carburetor (e.g., VM26SS or similar)
Fuel Type:
Unleaded gasoline (87 octane recommended)
Oil Type:
Yamalube 4W or equivalent SAE 10W-30 or 20W-40 motorcycle/ATV engine oil (check manual for specific viscosity)
Oil Capacity:
Approximately 1.5 - 1.8 liters (check manual for exact capacity with filter change)
System:
CDI (Capacitor Discharge Ignition)
Spark Plug:
NGK CR7E or similar (verify with manual)
Type:
Automatic transmission with torque converter and Hi/Lo range (often referred to as Ultramatic)
Type:
N/A (all models featured automatic)
Drive System:
Shaft drive to rear wheels (2WD), shaft drive to front and rear wheels (4WD)
Gear Reduction:
High and Low range gears for different terrains/towing needs
Type:
Yamalube High-Performance Gear Oil or equivalent SAE 80W hypoid gear oil (for final drive and 4WD gearbox)
Final Drive Capacity:
Approximately 0.25 - 0.35 liters (check manual for exact capacity)
Length:
Approx. 73.6 inches (1870 mm)
Width:
Approx. 43.3 inches (1100 mm)
Height:
Approx. 43.7 inches (1110 mm)
Wheelbase:
Approx. 49.2 inches (1250 mm)
Dry Weight Estimated:
Approx. 463 lbs (210 kg) for 2WD, slightly more for 4WD
Curb Weight Estimated:
Approx. 485 lbs (220 kg) (includes all necessary fluids)
Front Rack Capacity Estimated:
Approx. 44 lbs (20 kg)
Rear Rack Capacity Estimated:
Approx. 66 lbs (30 kg)
Towing Capacity Estimated:
Typically around 1102 lbs (500 kg)
Front Tire Size:
AT22x7-10 or similar
Rear Tire Size:
AT22x10-10 or similar
Wheel Bolt Pattern:
4x110 mm (typical for Yamaha)
Safety Standards:
Designed to meet relevant ATV safety standards of the era. Always operate responsibly and wear protective gear.
Braking System:
Hydraulic disc brakes front and rear
Parking Brake:
Mechanical parking brake
Handlebars:
Ergonomically designed handlebars for control
Lighting:
Dual headlights and a taillight/brake light for visibility
Engine Kill Switch:
Handlebar-mounted engine kill switch for quick shutdown
Oil Change:
Every 1,000 km or 6 months (check manual for precise interval and conditions)
Air Filter Cleaning:
Every 500 km or annual cleaning/replacement (depending on operating conditions)
Spark Plug Check:
Every 2,000 km or annually
Valve Adjustment:
Every 4,000 km or 2 years
Engine Oil Viscosity:
SAE 10W-30 or 20W-40 (check manual for optimal temperature range)
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid (check manual for specific recommendation)
Coolant Type:
N/A (Air-cooled engine)
Carburetor Fouling:
Can be prone to carburetor gumming if not run regularly or if stale fuel is used; requires cleaning and proper jetting.
Drive Belt Wear:
CVT drive belts can wear over time and require periodic inspection and replacement, especially under heavy load.
Carburetor Jetting:
Carburetor jetting may need adjustment for altitude changes or aftermarket exhaust/air filter modifications.
Starter Solenoid:
Occasional failure of the starter solenoid can prevent engine cranking.
Heritage:
Yamaha has a long-standing reputation for producing reliable and capable powersports vehicles, including a strong presence in the ATV market.
Timberwolf Lineage:
The Timberwolf was Yamaha's offering in the popular 250cc class utility ATV segment, known for its durability and ease of use.
Updates Within Generation:
While the core design remained consistent from 1992-2000, minor updates may have included cosmetic changes or minor component revisions (detailed in the manual).
Manufacturing Location:
Primarily manufactured in Japan, a hallmark of Yamaha quality
