🏷️ Basic Information Identification Make: Yamaha Model: YFM350ER Model Nickname: Big Bear Model Variant: 2WD (Rear-Wheel Drive) Generation Generation Code: First Generation (YFM350ER Series) Codes Engine Code: 350cc Air-Cooled 4-Stroke SOHC 👋 Introduction Market Position Atv Segment: Utility/Recreational ATV Target Audience: Outdoor enthusiasts, farmers, hunters, and recreational riders. Competitive Analysis Competitors Era: Honda FourTrax 300, Suzuki QuadSport LT-F250, Kawasaki Bayou 300. Key Features Vehicle Strengths: Reliability, torquey engine, comfortable suspension for its time, ease of maintenance. Manual Value Proposition: Essential resource for owners to maintain, diagnose, and repair their YFM350ER, extending its lifespan and performance. 📋 Manual Details Coverage Areas Covered Years: 1987, 1988, 1989, 1990 Primary Coverage: Comprehensive service and repair for Yamaha YFM350ER ATV Page Count Estimated Pages: High, exceeding 300 pages (typical for master service manuals of this era) Manual Type Manual Type: Master Service Manual Manual Category: Official Factory Service Manual Language Language: English Format File Format: PDF 📖 Manual Coverage Systems Covered Engine Mechanical: Complete disassembly, inspection, overhaul, and reassembly of the 350cc engine. Fuel System: Carburetor (Mikuni VM Series) tuning, cleaning, and rebuilding; fuel tank, lines, and petcock service. Ignition System: CDI ignition system, spark plug specifications, troubleshooting, and component testing. Exhaust System: Muffler and exhaust pipe inspection, maintenance, and potential replacement. Cooling System: Air-cooling system optimization, cylinder head temperature considerations. Transmission Drivetrain: 5-speed constant mesh transmission with reverse, clutch operation, final drive (chain and sprocket) maintenance. Suspension Front: Independent front suspension (IFS) maintenance, shock absorber adjustment, and fork seal replacement. Suspension Rear: Swingarm rear suspension, monoshock absorber adjustment, and linkage maintenance. Brakes: Front and rear drum brake system service, adjustment, and replacement of brake shoes. Wheels Tires: Wheel bearing inspection and service, tire pressure recommendations, and chain tension adjustment. Electrical System: Wiring diagrams, battery maintenance, lighting system, and starter motor operation. Frame Chassis: Frame inspection, steering system maintenance, and lubrication points. Bodywork Plastics: Fender, seat, and other body panel maintenance and removal/installation procedures. Procedures Included Routine Maintenance: Oil changes, filter replacements, spark plug checks, chain adjustments, brake adjustments, lubrication. Troubleshooting: Diagnostic charts and procedures for common problems across all major systems. Engine Rebuild: Detailed instructions for complete engine disassembly, part inspection, machining specifications, and reassembly. Transmission Overhaul: Step-by-step guide for transmission disassembly, gear inspection, and reassembly. Carburetor Rebuild: Instructions for dismantling, cleaning, reassembling, and adjusting the Mikuni VM carburetor. Suspension Service: Fork seal replacement, shock absorber adjustments, and linkage lubrication. Brake System Maintenance: Drum brake shoe replacement, adjustment procedures, and lever play settings. Electrical Diagnostics: Testing of ignition components, lighting circuits, and starting system. Technical Depth Depth Level: Expert-level diagnostic and repair procedures, suitable for professional technicians and experienced DIYers. Detail Level: Includes torque specifications, clearance measurements, timing procedures, and detailed diagrams. 📊 Manual Specifications File Format Compatibility: Compatible with all major operating systems (Windows, macOS, Linux). Searchability: Likely text-searchable PDF, allowing for quick access to specific topics. Print Quality Printability: Printable, allowing users to create physical copies for workshop use. Binding Type Binding Type Digital: N/A (Digital PDF Download) Paper Type Paper Type Digital: N/A (Digital PDF Download) Requirements Software Requirement: Adobe Acrobat Reader or compatible PDF viewer. Delivery Download Speed: Instant High-Speed Download ⚙️ Engine Specifications Primary Engine Engine Type: 4-stroke, SOHC, air-cooled Displacement: 348 cc Bore X Stroke: 83.0 mm x 64.5 mm Compression Ratio: 8.7:1 Performance Horsepower Estimated: Approx. 20-25 HP (at flywheel, may vary) Torque Estimated: Approx. 20-24 lb-ft (at flywheel, may vary) Fuel System Carburetor Model: Mikuni VM34SS (or similar variant) Fuel Type: Unleaded gasoline Lubrication Oil Capacity: 1.7 Liters (Dry) Recommended Oil: Yamalube 4 (or equivalent API SE, SF, SG or higher, SAE 10W-30, 10W-40, or 20W-40) Ignition Ignition System: CDI (Capacitor Discharge Ignition) Spark Plug Type: NGK DR8EA (or equivalent) 🔧 Transmission Standard Transmission Type: 5-speed constant mesh with reverse Clutch Type: Wet multi-plate Final Drive: O-ring sealed chain Features Gear Selection: Semi-automatic (foot shifter) Fluid Specifications Transmission Oil Type: Yamalube 4 (or equivalent API SE, SF, SG or higher, SAE 10W-30, 10W-40, or 20W-40) 📐 Dimensions Exterior Overall Length: Approx. 70.5 inches (1790 mm) Overall Width: Approx. 41.1 inches (1045 mm) Overall Height: Approx. 41.5 inches (1055 mm) Wheelbase: Approx. 47.2 inches (1200 mm) Ground Clearance: Approx. 4.9 inches (125 mm) Weights Dry Weight: Approx. 456 lbs (207 kg) Fuel Capacity: 2.6 gallons (9.8 Liters) Tires Front Tire Size: AT22x7-10 Rear Tire Size: AT22x10-10 Wheels Wheel Type: Steel, stamped Suspension Travel Front Suspension Travel: Approx. 5.5 inches (140 mm) Rear Suspension Travel: Approx. 5.1 inches (130 mm) 🛡️ Safety Features Ratings Atv Safety Standards: Designed to meet ANSI standards for All-Terrain Vehicles (may not have specific crash ratings like cars). Active Features Braking System: Front and rear drum brakes, parking brake. Passive Features Ergonomics: Designed for rider stability and control with handlebars and footwells. Lighting: Halogen headlights and taillight for visibility. 💡 Technology Features...