Atv Segment:
Utility/Recreational ATV
Target Audience:
Outdoor enthusiasts, farmers, hunters, and recreational riders.
Competitors Era:
Honda FourTrax 300, Suzuki QuadSport LT-F250, Kawasaki Bayou 300.
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.
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.
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.
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.
Compatibility:
Compatible with all major operating systems (Windows, macOS, Linux).
Searchability:
Likely text-searchable PDF, allowing for quick access to specific topics.
Printability:
Printable, allowing users to create physical copies for workshop use.
Binding Type Digital:
N/A (Digital PDF Download)
Paper Type Digital:
N/A (Digital PDF Download)
Software Requirement:
Adobe Acrobat Reader or compatible PDF viewer.
Download Speed:
Instant High-Speed Download
Engine Type:
4-stroke, SOHC, air-cooled
Bore X Stroke:
83.0 mm x 64.5 mm
Horsepower Estimated:
Approx. 20-25 HP (at flywheel, may vary)
Torque Estimated:
Approx. 20-24 lb-ft (at flywheel, may vary)
Carburetor Model:
Mikuni VM34SS (or similar variant)
Fuel Type:
Unleaded gasoline
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 System:
CDI (Capacitor Discharge Ignition)
Spark Plug Type:
NGK DR8EA (or equivalent)
Engine Oil Change:
Every 1000 km (600 miles) or 6 months, whichever comes first.
Oil Filter Change:
At every engine oil change.
Spark Plug Inspection:
Every 2000 km (1200 miles) or 12 months.
Air Filter Cleaning:
Every 500 km (300 miles) or 3 months, or more frequently in dusty conditions.
Chain Lubrication:
Every 500 km (300 miles) or after riding in wet conditions.
Chain Tension Adjustment:
Every 1000 km (600 miles) or 6 months.
Brake Adjustment:
As needed, checking lever play and drum clearance.
Transmission Oil Spec:
Yamalube 4 (or equivalent SAE 10W-30/10W-40)
Brake Fluid Type:
DOT 3 (typically, manual will specify)
Common Wear Items:
Brake shoes, rear brake cables, swingarm bushings, carburetor jets due to fuel variations.
Potential Problems:
Carburetor performance degradation over time, potential for overheating if air cooling is obstructed.
Importance Of Cleaning:
Regular cleaning of air filter and cooling fins is crucial for engine longevity and performance.
Yamaha Atv Legacy:
Yamaha has been a pioneer in the ATV industry, known for robust engineering and off-road performance.
Yfm350Er Introduction:
Introduced as a successor to earlier 250cc models, offering increased displacement and improved chassis design.
Key Updates Era:
Received minor updates throughout its production run, primarily in styling and accessory options.
Production Period:
1987-1990 for the YFM350ER model (part of the broader YFM350 lineage).
Manufacturing Location:
Japan (Typical for Yamaha ATVs of this era)
