🏷️ Basic Information

Make:

Yamaha

Model:

YFM400FAR

Model Designation:

Big Bear 400 4x4

Chassis Code:

YFM400FAR

Engine Code Prefix:

4TF

👋 Introduction

Category:

Utility ATV (All-Terrain Vehicle)

Target User:

Off-road enthusiasts, farmers, hunters, and utility users requiring reliable 4x4 capability.

Key Competitors:

Honda Foreman/Rancher, Suzuki King Quad, Polaris Sportsman, Kawasaki Bayou/Brute Force.

Distinguishing Features:

Yamaha's reputation for reliability and durability, robust 4x4 system, comfortable ride for its class, capable of moderate towing and cargo hauling.

Manual Value Proposition:

Provides factory-level repair and maintenance data, empowering owners to perform their own servicing, diagnostics, and repairs, saving time and money. Crucial for preserving the longevity and performance of the YFM400FAR.

📋 Manual Details

Vehicle Models Covered:

Yamaha YFM400FAR (and likely related YFM400 models with similar architecture)

Model Years Covered:

Likely covers the primary production year(s) of the YFM400FAR. Specific years should be confirmed by product listing, but typical for this generation would be early to mid-2000s.

Total Pages:

397

Type:

Complete Official Factory Service / Repair / Full Workshop Manual

Primary Language:

English

Delivery Format:

PDF Download

File Format:

PDF

📖 Manual Coverage

Engine Mechanical:

Comprehensive engine overhaul, disassembly, inspection, assembly, and tuning for the 386cc engine.

Engine Fuel System:

Carburetor (likely Mikuni BSR33) service, adjustment, and rebuilding; fuel pump operation; fuel tank and lines.

Engine Ignition System:

CDI unit, ignition coil, spark plug, timing checks, and troubleshooting.

Transmission Drivetrain:

Complete coverage of the automatic transmission (likely Ultramatic), including gearcase, drive clutch, driven clutch, belts, and drive shafts.

4X4 System:

Operation and repair of the on-command 4WD system, differential, drive axles, and CV joints.

Suspension Steering:

Front and rear suspension components (independent front, swingarm rear), shock absorbers, steering linkage, tie rods, and wheel bearings.

Braking System:

Front and rear brake systems, including hydraulic lines, master cylinders, calipers, brake pads, brake shoes, and parking brake.

Electrical System:

Wiring diagrams, battery, charging system (stator, regulator/rectifier), starter motor, lighting (headlights, taillights, brake lights), and electrical component testing.

Cooling System:

Radiator, fan operation, coolant flow, and thermostat.

Chassis Frame:

Frame inspection and repair, body panels, fenders, racks, and seat.

Routine Maintenance:

Oil changes, filter replacements, lubrication points, valve clearance adjustment, spark plug replacement, air filter service.

Troubleshooting:

Systematic diagnostic procedures for common problems across all major systems, including error codes and symptom-based troubleshooting.

Component Repair Rebuild:

Detailed step-by-step instructions for disassembling, inspecting, cleaning, repairing, and reassembling all major mechanical and electrical components.

Wiring Diagrams:

Complete and clearly labeled electrical wiring schematics for easy diagnosis and repair.

Torque Specifications:

All critical fastener torque values for engine, chassis, and suspension components.

Special Tools:

Identification and usage of Yamaha-specific or recommended special tools for certain procedures.

Depth:

Full Workshop Level - covers everything from basic maintenance and fluid changes to complete engine rebuilds, transmission overhauls, and complex electrical diagnostics.

📊 Manual Specifications

Searchability:

Keyword searchable PDF, allowing for quick access to specific topics and components.

Printability:

Printable, enabling users to create hard copies for garage or field use.

Zoom Functionality:

Supports zoom in/out for detailed viewing of diagrams, schematics, and text.

Binding:

Digital (PDF download) - no physical binding.

Paper Quality:

N/A (Digital format)

⚙️ Engine Specifications

Engine Type:

4-Stroke, SOHC, Air-Cooled

Displacement:

386 cc

Bore X Stroke:

82 mm x 71.2 mm (typical for this engine)

Compression Ratio:

9.2:1 (typical)

Horsepower:

Approximately 21-23 HP (estimated, actual figures vary)

Torque:

Approximately 28-30 Nm (estimated, actual figures vary)

Fuel Delivery:

Carburetor (Mikuni BSR33 twin-needle, constant velocity)

Fuel Type:

Unleaded gasoline (Octane rating to be specified in manual, typically 87 or higher)

Ignition System:

CDI (Capacitor Discharge Ignition)

Spark Plug Type:

NGK CR7E or equivalent (specific to manual)

Oil Type:

Yamalube 4 (or equivalent 10W-40 API SG or higher, SJ or higher, SAE 20W-40 Type SE, SD, SC engine oil)

Oil Capacity:

Approx. 3.5 L (without filter change), 3.7 L (with filter change) - specific capacities to be confirmed in manual.

🔧 Transmission

Type:

Automatic (Yamaha Ultramatic Transmission - CVT)

Drive System:

Shaft Drive (with selectable 2WD/4WD)

Clutch:

Automatic centrifugal clutch with V-belt

Gear Reduction:

High, Low, Neutral, Reverse, Park

Gearcase Oil Type:

Yamalube Hypoid Gear Oil (or equivalent SAE 80 API GL-4)

Gearcase Oil Capacity:

Approx. 0.24 L (to be confirmed in manual)

📐 Dimensions

Length:

Approx. 2065 mm (81.3 in)

Width:

Approx. 1100 mm (43.3 in)

Height:

Approx. 1150 mm (45.3 in)

Wheelbase:

Approx. 1280 mm (50.4 in)

Dry Weight:

Approx. 262 kg (578 lbs)

Towing Capacity:

Up to 650 kg (1,430 lbs) (specification to be confirmed in manual)

Front Rack Capacity:

Approx. 45 kg (99 lbs)

Rear Rack Capacity:

Approx. 85 kg (187 lbs)

🛡️ Safety Features

Atv Safety:

ATVs are inherently more dangerous than cars; emphasis on protective gear (helmet, goggles, gloves, boots, long sleeves/pants) and safe operating practices as outlined by manufacturers and industry standards.

Braking:

Hydraulic disc brakes front and rear, plus parking brake.

4Wd Engagement:

On-command 2WD/4WD system for terrain adaptability.

Ergonomics:

Designed for rider comfort and control, with wide floorboards and comfortable seating position.

Lighting:

Dual halogen headlights, taillight, and brake light for visibility.

💡 Technology Features

Features:

Basic instrumentation: speedometer, odometer, trip meter, neutral/reverse indicators, 4WD indicator, high beam indicator. No advanced infotainment systems.

Features:

Limited. The primary 'assistance' is the on-command 4WD system and the automatic CVT transmission which simplifies operation.

Features:

None. This is a utility ATV focused on mechanical performance, not digital connectivity.

🔧 Maintenance

Engine Oil Change:

Every 3,000 km or 12 months, or more frequently under severe use (refer to manual for exact intervals).

Air Filter Cleaning:

Inspect every 1,000 km, clean as needed. Specific interval for wet/dry cleaning depends on conditions (refer to manual).

Spark Plug Check:

Check/replace every 6,000 km or 12 months (refer to manual).

Valve Clearance Adjustment:

Every 6,000 km (refer to manual).

Brake Fluid Type:

DOT 3 or DOT 4 (refer to manual for specific recommendation)

Coolant Type:

Permanent antifreeze coolant (ethylene glycol-based) with corrosion inhibitor (refer to manual for mix ratio, typically 50/50 water/antifreeze).

Common Wear Items:

CV boots, brake pads, wheel bearings, starter motor brushes, drive belts (CVT). Consistent maintenance is key to mitigating these.

Carburetor Tuning:

Carburetors can be sensitive to altitude and fuel quality; proper tuning as per the manual is essential for optimal performance and fuel economy.

Ultramatic Cvs Maintenance:

Regular inspection and cleaning of the CVT drive and driven clutches are vital for belt longevity and proper operation.

📚 Vehicle History

Yamaha Atv Legacy:

Yamaha has a long and respected history in ATV manufacturing, known for innovation and building durable, reliable machines since the early days of the industry.

Big Bear Lineage:

The Big Bear nameplate has been a staple in Yamaha's utility ATV lineup for decades, evolving through various engine sizes and features, consistently focusing on ruggedness and practicality.

Manufacturing Location:

Primarily manufactured in Japan by Yamaha Motor Corporation.

🏆 Awards & Recognition

Industry Awards:

While specific awards for the YFM400FAR may not be widely publicized, Yamaha ATVs consistently receive praise in enthusiast reviews for their reliability, durability, and value.

Consumer Reviews:

Generally positive, with owners often citing durability, capable 4x4 performance, and ease of maintenance as key strengths. Some mention a slightly rougher ride compared to more premium models.