Yamaha Grizzly 350 Service Manual

The Yamaha Grizzly 350 is a rugged all-terrain vehicle (ATV) designed for work and recreation. This service manual provides comprehensive information for maintenance, troubleshooting, and repair of the Grizzly 350 model. It covers engine, chassis, electrical systems, periodic maintenance, and specifications to ensure proper operation and longevity of your ATV. Below are key sections for safety, features, maintenance procedures, specifications, and troubleshooting.

Features at a Glance

Key components: 348cc air-cooled 4-stroke engine, Ultramatic automatic transmission with engine braking, On-Command 2WD/4WD with differential lock, independent double-wishbone front suspension, swingarm rear suspension, disc brakes, and durable steel frame.

Safety Precautions

Always follow safety guidelines to prevent injury and damage.

1. Wear appropriate safety gear: helmet, eye protection, gloves, boots, and protective clothing.
2. Inspect ATV before each ride: check tires, brakes, lights, and controls.
3. Perform maintenance with engine off and cool; disconnect battery for electrical work.
4. Use proper tools and torque specifications during repairs.
5. Work in a well-ventilated area; avoid open flames near fuel system.

WARNING! ATV operation requires skill and caution. Never operate under influence of drugs/alcohol. Keep hands and feet away from moving parts during maintenance.

Periodic Maintenance

Regular maintenance ensures optimal performance and safety.

1. Pre-ride inspection: Check tires, brakes, lights, fluid levels, and throttle operation.
2. Engine oil: Change every 100 hours or 6 months; use Yamalube 4-stroke oil or equivalent.
3. Oil filter: Replace with every oil change.
4. Air filter: Clean every 20-50 hours; replace if damaged.
5. Spark plug: Inspect and clean every 100 hours; replace as needed.
6. Drive chain: Clean and lubricate every 20 hours; adjust tension to 1.2-1.6" free play.
7. Brake fluid: Check level and condition every 100 hours; replace every 2 years.
8. Wheel bearings: Inspect every 200 hours; repack with grease if necessary.

CAUTION! Use only Yamaha-approved parts and fluids. Tighten fasteners to specified torque values.

Specifications

• Engine Type: 4-stroke, SOHC, air-cooled, single cylinder.
• Displacement: 348cc.
• Bore x Stroke: 83.0 mm x 64.5 mm.
• Compression Ratio: 8.3:1.
• Fuel System: Mikuni BSR33 carburetor.
• Ignition System: DC-CDI.
• Starting System: Electric starter with auxiliary recoil.
• Transmission: Ultramatic automatic V-belt with high and low ranges, reverse.
• Final Drive: Shaft drive with On-Command 2WD/4WD.
• Suspension Front: Independent double-wishbone, 6.7" travel.
• Suspension Rear: Swingarm, 7.1" travel.
• Brakes Front: Dual hydraulic disc.
• Brakes Rear: Hydraulic disc.
• Tires Front: AT25 x 8-12.
• Tires Rear: AT25 x 10-12.
• Fuel Capacity: 4.8 gal (18.2 L).
• Oil Capacity: 2.1 qt (2.0 L) with filter change.

Engine Service

Access engine components by removing seat and side panels.

Valve Clearance: Intake 0.10-0.15 mm (0.004-0.006 in), Exhaust 0.15-0.20 mm (0.006-0.008 in). Adjust with engine cold.

Oil Change: Warm engine, drain oil, replace filter, refill with 2.1 qt of SAE 10W-30 or 10W-40.

Carburetor: Adjust idle speed to 1400-1500 rpm; clean jets if engine runs rough.

Cooling: Ensure cooling fins are clean; no liquid coolant system.

Chassis & Suspension

Inspect frame for cracks or damage. Lubricate suspension pivots every 100 hours.

1. Front suspension: Check A-arm bushings and ball joints for wear.
2. Rear suspension: Inspect swingarm pivot and shock absorber.
3. Steering: Check tie rods and steering stem bearings; adjust if loose.
4. Wheels & Tires: Inspect for damage; maintain tire pressure (Front: 3.6 psi, Rear: 3.6 psi for standard load).

Tip: Torque axle nuts to 65 ft-lb (88 Nm).

Electrical System

12V DC system with battery, starter, and lighting.

1. Battery: Check electrolyte level; maintain charge; voltage should be 12.6V or higher.
2. Fuses: Located under seat; replace with same amperage if blown.
3. Lights: Inspect headlights, taillight, and brake light for operation.
4. Wiring: Check for frayed wires or loose connections, especially near handlebars and engine.

WARNING! Disconnect negative battery terminal before electrical work to prevent shorts.

Fuel System

Mikuni BSR33 carburetor with manual choke.

1. Fuel tank: Clean sediment cup every 100 hours.
2. Fuel filter: Replace annually or if clogged.
3. Carburetor adjustment: Pilot screw factory set; adjust idle mixture if necessary.
4. Throttle cable: Check for smooth operation; lubricate if sticky.

CAUTION! Gasoline is flammable. No smoking during fuel system service.

Transmission & Drive

Ultramatic automatic transmission with V-belt drive.

1. Transmission fluid: Change every 200 hours; use Yamaha Ultramatic Transmission Oil.
2. V-belt: Inspect for wear or cracks every 100 hours; replace if damaged.
3. Drive shaft: Check for leaks at boots; lubricate splines every 200 hours.
4. On-Command system: Test 2WD/4WD and differential lock operation; ensure engagement lever moves freely.

WARNING! Do not operate with damaged drive belt; may cause loss of drive.

Troubleshooting

Reset: For electronic issues, disconnect battery for 10 minutes to reset ECU.

Service: For complex repairs, consult Yamaha dealer.

Warranty & Support

Yamaha Limited Warranty: 6 months for commercial use, 1 year for recreational use from purchase date. Warranty covers defects in materials/workmanship; does not cover normal wear, improper maintenance, or accidents. Keep receipts and maintenance records. For support, contact Yamaha Motor Corporation, USA at 1-800-88-YAMAHA or visit www.yamahamotorsports.com. Use genuine Yamaha parts for repairs to maintain warranty and performance.