Vehicle Segment:
Mid-size utility ATV, known for its reliable performance and versatility in recreational and light utility applications.
Key Competitors:
Honda FourTrax 300/350, Suzuki QuadSport 250/300, Kawasaki Bayou 300/400.
Vehicle Strengths:
Durable air-cooled engine, reliable shaft drive, comfortable suspension for its class, robust chassis.
Manual Benefit:
Enables DIY repairs, reduces mechanic costs, ensures proper maintenance for longevity, and aids in diagnosing complex issues.
Primary Coverage:
Maintenance, Repair, Overhaul, Troubleshooting, Specifications, Electrical Systems, Chassis Components, Carburetion
Estimated Page Count:
200-400 pages (typical for a factory service manual of this era)
Manual Type:
Factory Service Repair Manual
Engine System:
Complete overhaul, top-end (cylinder, piston, valves), bottom-end (crankshaft, bearings), cooling system, lubrication system
Fuel System:
Carburetor disassembly, cleaning, adjustment, fuel pump, fuel lines, fuel tank maintenance
Transmission System:
Clutch operation and adjustment, gear shifting mechanisms, transmission fluid checks and changes
Drivetrain:
Driveshaft inspection and maintenance, rear differential lubrication and inspection
Suspension:
Front and rear suspension component inspection, shock absorber servicing, spring and linkage maintenance
Brakes:
Brake caliper service, brake pad replacement, brake fluid bleeding, brake line inspection
Electrical System:
Ignition system (spark plug, coil, CDI), starting system (starter motor, battery), charging system (stator, regulator/rectifier), lighting, wiring diagrams, troubleshooting electrical faults
Chassis:
Frame inspection, steering system maintenance, wheel and tire checks, body panel removal and installation
Maintenance Procedures:
Periodic inspection schedule, lubrication points and intervals, filter replacement (air, oil), spark plug gap and replacement
Repair Procedures:
Step-by-step instructions for component disassembly, reassembly, and adjustment
Overhaul Procedures:
Detailed procedures for engine and transmission rebuilds
Troubleshooting Guides:
Diagnostic trees for common problems, identifying symptoms and potential causes
Diagnostic Capabilities:
Advanced diagnostics for engine performance, electrical system faults, and mechanical issues
Rebuild Depth:
Comprehensive instructions for complete engine and transmission rebuilds, including component tolerances and specifications
Engine Type:
4-stroke, SOHC, air-cooled
Bore X Stroke:
83 mm x 64.5 mm (Typical for this engine family)
Compression Ratio:
8.8:1 (Typical)
Valve Configuration:
SOHC, 2 valves per cylinder
Horsepower:
Approx. 21-23 HP (Estimated, actual may vary slightly)
Torque:
Approx. 20-22 lb-ft (Estimated)
Carburetor Model:
Mikuni BNS32 (Likely, common for Yamaha 350s of this era)
Fuel Type:
Unleaded gasoline
Fuel Tank Capacity:
Approx. 3.17 US gal (12 liters)
Oil Type:
Yamalube 4 (or equivalent API SG, SAE 20W-40, JASO MA)
Oil Capacity With Filter:
Approx. 1.77 US qt (1.68 L)
Length:
Approx. 76.5 inches (1945 mm)
Width:
Approx. 42.1 inches (1070 mm)
Height:
Approx. 42.3 inches (1075 mm)
Wheelbase:
Approx. 49.2 inches (1250 mm)
Dry Weight:
Approx. 478 lbs (217 kg)
Ground Clearance:
Approx. 6.7 inches (170 mm)
Engine Oil Change:
Every 100 hours or 6 months (whichever comes first), or more frequently under severe use.
Air Filter Cleaning:
Every 20 hours or monthly, more often in dusty conditions.
Spark Plug Inspection:
Every 100 hours or 6 months.
Final Drive Oil Change:
Every 100 hours or 6 months.
Engine Oil Specification:
Yamalube 4 (or SAE 20W-40 API SG, JASO MA)
Final Drive Oil Specification:
Yamaha Hypoid Gear Oil (or SAE 80 API GL-4)
Brake Fluid Specification:
DOT 3 or DOT 4.
Common Wear Items:
Tie rod ends, ball joints, wheel bearings, brake pads, swingarm bushings, drive shaft U-joints, carburetor jets (clogging).
Engine Concerns:
Carbon buildup on valves due to air-cooling, potential for starter clutch wear, carburetor adjustment sensitivity to altitude/fuel quality.
Electrical Concerns:
Stator failure, regulator/rectifier issues, starter solenoid wear (less common but possible).
Manufacturer:
Yamaha Motor Company is a Japanese manufacturer of motorcycles, marine products, and motorized recreational vehicles, known for its innovation and performance.
Wolverine Lineage:
The Wolverine series has been a staple for Yamaha, evolving from earlier utility and recreational models to offer a balance of capability and comfort. The 350cc engine has been a reliable workhorse for many years.
Production Period:
The YFM Wolverine 350 was produced across various years, with the 2003 model representing a mid-cycle iteration of this popular platform.
