Target Audience:
Owners, DIY mechanics, and professional technicians working on the 1991 Yamaha YFM 350 Wolverine ATV.
Manual Value Proposition:
Provides essential technical data and procedures to ensure the longevity and optimal performance of the YFM 350 Wolverine, reducing reliance on expensive professional services.
Content Highlight:
Focuses on enabling users to not only fix existing problems but also to proactively maintain the vehicle for future reliability and problem prevention.
Systems Covered:
General Information, Specifications, Periodic Checks and Adjustment, Engine, Cooling System, Carburetion, Drive Train, Chassis, Electrical, Troubleshooting
Estimated Page Count:
Refer to actual document, typically 300-500 pages for a comprehensive service manual of this era.
Manual Type:
Service and Repair Manual
Engine Mechanical:
Detailed disassembly, inspection, repair, and reassembly of engine components including cylinder, piston, crankshaft, connecting rod, camshaft, valve train, timing, and more.
Cooling System:
Inspection, testing, repair, and replacement of radiator, coolant, fan, hoses, thermostat, and related components.
Fuel System:
Carburetor adjustment, cleaning, overhaul, fuel pump, fuel lines, and fuel tank maintenance.
Drivetrain:
Maintenance and repair of gearbox, clutch, drive shafts, differential (if applicable), and final drive system.
Chassis:
Suspension system (front and rear), steering system, braking system (hydraulic lines, calipers, pads, rotors), and frame inspection/repair.
Electrical System:
Wiring diagrams, ignition system, lighting, battery, starter, charging system, and troubleshooting electrical faults.
Preventative Maintenance:
Scheduled maintenance checks, lubrication points, filter replacements, and fluid changes.
Diagnostic Procedures:
Systematic troubleshooting guides for identifying and resolving common and uncommon issues.
Repair Procedures:
Step-by-step instructions for component removal, installation, and repair, often with torque specifications.
Adjustment Procedures:
Detailed instructions for adjusting various systems like carburetor idle, brakes, and clutch.
Depth Of Coverage:
Comprehensive, covering everything from basic checks and adjustments to complete engine and transmission rebuilds, electrical diagnostics, and chassis repairs.
Searchability:
Likely text-searchable if the PDF was created from a digital source or high-quality scan.
Accessibility:
Accessible on Windows, Mac, smartphones, and tablets via Adobe PDF Reader or compatible applications.
Printability:
Printable, allowing for physical copies for workshop use.
Binding:
N/A (Digital format)
Paper Quality:
N/A (Digital format)
Engine Type:
Air-cooled, 4-stroke, SOHC
Engine Displacement:
348cc (21.2 cu. in.)
Bore X Stroke:
82.0 mm x 64.5 mm (3.23 in x 2.54 in) (Estimate based on common specifications for this engine) - *Confirm with manual*
Compression Ratio:
8.7:1 (Estimate based on common specifications for this engine) - *Confirm with manual*
Horsepower:
Typically in the range of 20-25 HP (Estimate) - *Confirm with manual*
Torque:
Typically in the range of 25-30 lb-ft (Estimate) - *Confirm with manual*
Carburetor Type:
Mikuni VM Series (e.g., VM32SS or similar) - *Confirm with manual*
Fuel Type:
Unleaded gasoline
Fuel Tank Capacity:
Approx. 2.6 gallons (9.8 L) - *Confirm with manual*
Transmission Type:
5-speed manual with automatic clutch and reverse
Transmission Options:
N/A for this model year
Clutch Type:
Wet, multi-disc, automatic engagement
Final Drive:
Shaft drive, enclosed oil bath
Overall Length:
Approx. 73.6 inches (1870 mm) - *Confirm with manual*
Overall Width:
Approx. 42.1 inches (1070 mm) - *Confirm with manual*
Overall Height:
Approx. 43.1 inches (1095 mm) - *Confirm with manual*
Wheelbase:
Approx. 49.2 inches (1250 mm) - *Confirm with manual*
Dry Weight:
Approx. 474 lbs (215 kg) - *Confirm with manual*
Ground Clearance:
Approx. 5.5 inches (140 mm) - *Confirm with manual*
Atv Safety Standards:
Adheres to industry safety standards applicable at the time of manufacture.
Braking System:
Hydraulic disc brakes (front and rear) for effective stopping power.
Lighting System:
Halogen headlights and taillight for visibility.
Suspension Design:
Independent front suspension and swingarm rear suspension for stable handling and rider comfort.
Tire Design:
Knobby tires for traction on various terrains.
Oil Change Interval:
Typically every 100 hours or annually. Specifics provided in the manual.
Air Filter Cleaning:
Recommended for every 20-40 hours of operation or as needed based on operating conditions.
Spark Plug Replacement:
Typically every 100 hours or annually. Specifics provided in the manual.
Engine Oil Type:
Yamalube or equivalent API SG classification SAE 10W-30 or 20W-40. Specific viscosity may depend on ambient temperature. Refer to manual for exact recommendation.
Engine Oil Capacity:
Approx. 1.75 US qt (1.65 L) with filter change. *Confirm with manual*
Transmission Oil Type:
Yamalube SAE 80 Hypoid Gear Oil or equivalent. *Confirm with manual*
Transmission Oil Capacity:
Approx. 0.63 US qt (0.6 L). *Confirm with manual*
Coolant Type:
Not applicable (Air-cooled engine)
Common Wear Items:
Brake pads, clutch components, wheel bearings, and suspension bushings are common wear items on ATVs of this age and usage.
Carburetor Performance:
Carburetors can be prone to clogging from fuel varnish if the vehicle sits for extended periods. Regular cleaning and adjustment are key.
Yamaha Atv Legacy:
Yamaha has a long-standing history of innovation and performance in the ATV market, often setting benchmarks for durability and capability.
Wolverine Lineage:
The Wolverine nameplate has been associated with reliable, capable ATVs, with models like the YFM 350 Wolverine being a popular choice for recreational and utility use in its era.
Manufacturing Location:
Likely manufactured in Japan or by Yamaha's global manufacturing facilities. Specifics for the 1991 model may vary.
