Market Segment:
Mid-size utility ATV (All-Terrain Vehicle) for recreational and light utility use.
Target Audience:
Riders seeking a reliable, capable, and relatively simple-to-maintain ATV for trail riding, light farm work, and recreational exploration.
Key Competitors:
Honda FourTrax 300/350, Suzuki King Quad 300, Kawasaki Bayou 300.
Engine Type:
Proven, reliable air-cooled 348cc four-stroke engine.
Drivetrain Options:
Available in 2WD and 4WD configurations, offering versatility for different terrains.
Suspension Design:
Independent front suspension (on many models) and swingarm rear suspension for a balance of comfort and capability.
Ease Of Maintenance:
Designed for straightforward maintenance, making it popular with DIY owners.
Systems Covered:
Engine, Drivetrain (Transmission, Final Drive), Suspension, Steering, Brakes, Electrical System, Fuel System, Cooling System, Frame, Bodywork, Carburetor, Exhaust System, Chassis Components, Wheel and Tire Specifications, Troubleshooting.
Page Count:
Estimated 400-600 pages (typical for comprehensive service manuals of this era, exact count not provided in product info).
Manual Type:
Service and Repair Manual
Engine:
Detailed disassembly, inspection, assembly, and adjustment procedures for the 348cc air-cooled 4-stroke SOHC engine. Includes valve adjustment, piston and cylinder inspection, crankshaft and connecting rod checks, timing chain/belt replacement, and more.
Drivetrain:
Comprehensive coverage of the transmission (manual or automatic, depending on model year), clutch, drive shafts, differential, and final drive unit. Includes fluid change procedures, bearing checks, and gear inspection.
Suspension:
Front and rear suspension component service, including A-arms, shock absorbers (struts), springs, bushings, and pivot points. Adjustment of pre-load and damping where applicable.
Steering:
Steering column, tie rods, steering knuckles, and ball joint inspection and replacement. Adjustment of steering play and alignment checks.
Brakes:
Front and rear brake system maintenance, including hydraulic fluid replacement and bleeding, caliper and master cylinder service, brake pad and shoe replacement, rotor inspection, and parking brake adjustments.
Electrical System:
Wiring diagrams, ignition system service (spark plug, coil, CDI unit), charging system (stator, regulator/rectifier), starting system (starter motor, battery), lighting, and accessory circuits.
Fuel System:
Carburetor disassembly, cleaning, adjustment, and reassembly. Fuel tank, fuel lines, and fuel pump (if applicable) service. Fuel filter replacement.
Cooling System:
Air-cooled engine cooling principles and maintenance, if applicable (though predominantly air-cooled). Overheating causes and troubleshooting.
Frame And Bodywork:
Frame inspection for damage, body panel removal and installation, seat service, and general chassis component maintenance.
Maintenance Procedures:
Routine checks, lubrication points, filter changes (oil, air, fuel), fluid level checks and top-offs, battery maintenance, and general cleaning procedures.
Troubleshooting:
Systematic diagnostic charts and procedures for identifying and resolving common mechanical and electrical problems.
Repair Procedures:
Step-by-step instructions for the disassembly, repair, and reassembly of all major vehicle components and systems.
Adjustment Procedures:
Carburetor idle and mixture adjustments, valve clearance adjustments, brake adjustments, chain slack adjustment (if applicable), and steering alignment adjustments.
Special Tools:
Identification of specific tools required for certain repair or adjustment procedures, often with diagrams.
Technical Depth:
Comprehensive, covering everything from basic rider maintenance to complete engine and transmission overhauls. Suitable for both novice DIY enthusiasts and experienced mechanics.
Engine Type:
4-stroke, SOHC, air-cooled, single-cylinder
Bore X Stroke:
Approximately 83.0 mm x 64.5 mm (exact figures may vary slightly).
Compression Ratio:
Typically around 9.2:1
Horsepower:
Estimated 18-20 HP (at flywheel, actual may vary by year and tuning).
Torque:
Estimated 18-20 lb-ft (at flywheel, actual may vary by year and tuning).
Carburetor:
Mikuni VM Series (e.g., VM34 or similar).
Fuel Type:
Unleaded gasoline (91 octane or higher recommended).
Oil Type:
Yamalube 4 (or equivalent 10W-40 API SE, SF, SG or higher, JASO MA).
Oil Capacity:
Approx. 1.8 L (1.9 US qt) with filter change. Specific capacity detailed in manual.
Ignition System:
CDI (Capacitor Discharge Ignition) with electronic advance.
Spark Plug Type:
NGK CR7HSA or equivalent.
Cooling Method:
Forced air cooling.
Transmission Type:
5-speed manual with automatic clutch (constant mesh).
Optional Transmission:
Some earlier models or specific configurations might have featured different transmission setups, but 5-speed manual with auto-clutch is standard for the majority of this generation.
Clutch Type:
Wet, multi-disc, automatic centrifugal clutch.
Drive System:
Shaft drive to rear differential; 2WD or 4WD selectable with shaft drive to front differential.
Transmission Oil Type:
Yamalube Gear Oil (or equivalent SAE 80 Hypoid Gear Oil).
Transmission Oil Capacity:
Approx. 0.8 L (0.85 US qt). Specific capacity detailed in manual.
Overall Length:
Approx. 1995 mm (78.5 in)
Overall Width:
Approx. 1095 mm (43.1 in)
Overall Height:
Approx. 1060 mm (41.7 in)
Wheelbase:
Approx. 1260 mm (49.6 in)
Dry Weight:
Approx. 230 kg (507 lbs) for 2WD, higher for 4WD.
Curb Weight:
Varies by model, typically around 240-260 kg.
Max Load Capacity:
Typically around 150-200 kg (rider + cargo).
Towing Capacity:
Typically rated for 500 kg (1102 lbs) for towing.
Front Tire Size:
AT22x7-10 or similar.
Rear Tire Size:
AT22x10-10 or similar.
Front Wheel Size:
10 x 5.5
Rear Wheel Size:
10 x 8.0
Ground Clearance:
Approx. 220 mm (8.7 in).
Safety Ratings:
ATVs are not rated by NHTSA or IIHS. Safety depends on rider operation and adherence to precautions outlined in the owner's manual and this service manual.
Active Safety Features:
Full-size handlebars, thumb throttle, foot brake pedals, front and rear racks for carrying gear. (No electronic aids like ABS or traction control).
Passive Safety Features:
Engine braking (provided by the 4-stroke engine and transmission), durable chassis construction, protective fenders, and the importance of wearing appropriate riding gear (helmet, boots, gloves, eye protection).
Engine Oil Change:
Every 100 hours or 6 months, whichever comes first. Refer to manual for exact interval based on usage conditions.
Air Filter Cleaning:
Every 20 hours or as needed in dusty conditions. Replacement every 100 hours or annually.
Spark Plug Replacement:
Every 200 hours or annually. Check gap periodically.
Gear Oil Change:
Every 6 months or annually. Check manual for specific hours.
Valve Adjustment:
Every 200 hours or annually. Critical for engine performance and longevity.
Brake Fluid Flush:
Every 12 months or as needed.
Engine Oil Specification:
Yamalube 4 (or SAE 10W-40 API SE, SF, SG, SH, SJ, SL, SM, SN, SO or higher, JASO MA)
Transmission Oil Specification:
Yamalube Gear Oil (or SAE 80 Hypoid Gear Oil)
Brake Fluid Specification:
DOT 3 or DOT 4 hydraulic brake fluid.
Coolant Specification:
N/A (Air-cooled engine).
Common Issues:
Carburetor gumming/fouling due to infrequent use or stale fuel, carburetor jetting issues at higher altitudes, wear on suspension bushings, starter motor reliability, rear differential seal leaks, and drive shaft U-joint wear. Some models may experience clutch wear over time.
Preventative Maintenance:
Regular use and proper fuel stabilizer during storage are crucial for carburetor health. Periodic inspection of suspension and drivetrain components for wear and proper lubrication is recommended.
Brand Heritage:
Yamaha has a long history in motorsports and powersports, known for innovation and reliability in motorcycles and ATVs. The Wolverine line is a key part of their ATV legacy.
Model Evolution:
The YFM350 Wolverine was a popular model, evolving from earlier Yamaha utility ATVs. This 1995-2004 generation represents a significant period of its development, offering a balance of performance and utility before newer, more technologically advanced models were introduced.
Production Period:
The YFM350 Wolverine was in production for a significant period, with this specific manual covering the 1995-2004 iterations, which saw relatively minor updates during this timeframe, maintaining core mechanicals.
Manufacturing Location:
Yamaha powersports vehicles are typically manufactured in Japan and/or the United States.
