Positioning:
A capable 4x4 utility ATV designed for off-road use, recreational riding, and light work tasks. Competes in the mid-size utility ATV segment.
Competitors:
Honda FourTrax 300 4x4, Kawasaki Bayou 300 4x4, Suzuki QuadRunner 300 4x4, Polaris Sportsman 400 (depending on specific year comparison).
Distinctive Features:
Reliable 4x4 drivetrain, durable chassis, practical utility focus, Yamaha's reputation for quality and longevity.
Value:
This manual provides the essential technical knowledge for owners and mechanics to maintain, diagnose, and repair the Yamaha Timberwolf 4x4 YFB250, ensuring its operational readiness and longevity.
Primary Coverage:
Comprehensive service, repair, and maintenance
Secondary Coverage:
Electrical diagrams, troubleshooting, fluid capacities
Estimated Page Count:
Likely 300-600+ pages (typical for a comprehensive service manual of this era, though not explicitly stated)
Type:
Service and Repair Manual
Format:
PDF (Downloadable)
Engine Mechanical:
Engine removal/installation, cylinder head/valve, cylinder/piston, crankshaft/primary shaft, crankcase, transmission, sub-transmission, clutch, gearshift linkage
Fuel System:
Fuel system components, carburetor servicing, fuel tank, fuel lines
Electrical System:
Battery/charging system, ignition system, electric starter, switches, wiring diagrams
Chassis And Suspension:
Front wheel/suspension, rear wheel/suspension, hydraulic brake system
Lubrication And Fluids:
Lubrication points, fluid capacities (engine oil, transmission oil, brake fluid, coolant if applicable)
Routine Maintenance:
Inspection, adjustment, lubrication, fluid changes
Major Repairs:
Engine rebuilding, transmission overhaul, suspension component replacement
Diagnostics:
Troubleshooting guides, common issues, diagnostic procedures
Electrical Repair:
Wiring harness repair, component testing, electrical fault finding
Depth:
Comprehensive, covering everything from basic maintenance to complete engine and transmission rebuilds, with detailed diagrams.
Engine Type:
Four-stroke, SOHC
Displacement:
230cc to 250cc (typically around 230cc for early models, potentially variations within the range)
Cooling System:
Air-cooled
Bore X Stroke:
Specifics vary but common for this class: e.g., ~69mm x 64mm
Horsepower Estimate:
Approximately 17-20 HP (typical for this engine size and class)
Torque Estimate:
Approximately 14-16 lb-ft (typical for this engine size and class)
Fuel Delivery:
Carburetor (likely a Mikuni single barrel)
Fuel Type:
Unleaded Gasoline
Valve Train:
SOHC (Single Overhead Camshaft)
Transmission Type:
Automatic (CVT - Continuously Variable Transmission) with Reverse
Optional Transmission:
N/A (CVT was standard)
Drive System:
4WD (Shaft drive)
Gear Reduction:
Includes a sub-transmission for high/low range gearing (indicated by 'Sub transmission' in contents).
Transmission Fluid Type:
Specific gear oil type required, consult manual for exact specification (e.g., SAE 10W-30 or 10W-40 ATV gear oil).
Length Estimate:
~74-78 inches (typical for this class)
Width Estimate:
~42-45 inches (typical for this class)
Height Estimate:
~44-47 inches (typical for this class)
Dry Weight Estimate:
~450-500 lbs (typical for this class)
Ground Clearance Estimate:
~7-9 inches (typical for this class)
Front Rack Capacity Estimate:
~50-75 lbs
Rear Rack Capacity Estimate:
~100-150 lbs
Front Tire Size Common:
AT23x8-12 or similar
Rear Tire Size Common:
AT23x10-10 or AT23x11-10 or similar
Wheel Bolt Pattern:
Typically 4-stud, specific bolt circle diameter needs manual verification.
Safety Standards:
Adheres to relevant ATV safety standards of its time (e.g., ANSI).
Braking System:
Hydraulic disc brakes front and rear (typical).
Parking Brake:
Typically a separate mechanical parking brake.
Throttle Limiter:
Some models may have adjustable throttle limiters for new riders.
Infotainment System:
N/A (Basic ATV functionality, no infotainment system in the modern sense).
Driver Assistance Features:
N/A (Focus on mechanical systems and basic 4x4 operation).
Connectivity Features:
N/A
Headlights:
Dual headlights for illumination.
Taillight:
Rear taillight/brakelight for visibility.
Oil Change Interval:
Typically every 1000 km or 6 months (consult manual for precise recommendation).
Air Filter Cleaning:
Regular inspection and cleaning/replacement recommended based on operating conditions (e.g., every 100-200 operating hours or as needed in dusty environments).
Spark Plug Replacement:
Recommended replacement every 2000-3000 km or as per manual's specific interval.
Engine Oil Type:
Yamalube 4 (or equivalent JASO MA certified 10W-30 or 10W-40 motorcycle/ATV oil).
Engine Oil Capacity:
Approximately 1.8-2.0 liters (check dipstick/manual).
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid.
Coolant Type:
Not applicable, as the engine is air-cooled.
Common Wear Items:
CVT belt wear, brake pad wear, suspension bushings, carburetor cleaning due to fuel contamination.
Potential Electrical Issues:
Corrosion on connectors, aging starter motor brushes, CDI unit (though generally reliable).
Carburetor Cleaning:
Frequent cause of starting/running issues; requires periodic cleaning and adjustment.
Starting Problems:
Check battery, spark plug, fuel flow, and ignition system components.
Yamaha Atv Legacy:
Yamaha has a long and respected history in ATV manufacturing, known for innovation and durability since the introduction of the ATV. The Timberwolf contributes to this legacy.
Timberwolf Series:
The Timberwolf was Yamaha's entry into the mid-size utility ATV market, offering a balance of capability and value. It was often considered a more affordable alternative to larger utility models while retaining essential 4x4 functionality.
Production Period:
Produced from approximately 1993 through 2000, with minor updates throughout its lifecycle.
