1988 Yamaha Warrior 350 Manual

The 1988 Yamaha Warrior 350 is a high-performance sport ATV featuring a 348cc 4-stroke SOHC engine, 5-speed manual transmission with reverse, shaft drive system, independent rear suspension, dual hydraulic disc brakes, and rugged off-road capabilities. This manual covers safety procedures, maintenance schedules, technical specifications, troubleshooting, and repair procedures for optimal performance and longevity.

Features at a Glance

Key components: 348cc air-cooled 4-stroke engine, 5-speed transmission with reverse, shaft final drive, independent rear suspension, dual hydraulic disc brakes.

Safety Information

Always wear proper safety gear and follow operating procedures.

1. Always wear DOT-approved helmet, eye protection, gloves, and protective clothing.
2. Never operate under influence of alcohol or drugs.
3. Inspect ATV before each use for proper tire pressure, brake function, and fluid levels.
4. Ride only in designated areas and avoid public roads.
5. Do not carry passengers - designed for single rider only.

WARNING! This ATV can be hazardous to operate. Always follow safety guidelines and never exceed your skill level.

Controls and Instruments

Familiarize yourself with all controls before operation.

Specifications

• Engine: 348cc 4-stroke SOHC, air-cooled
• Bore x Stroke: 83.0 x 64.5mm
• Compression Ratio: 9.2:1
• Carburetor: Mikuni BS34 34mm
• Ignition: CDI electronic ignition
• Starting System: Electric start with backup kick starter
• Transmission: 5-speed manual with reverse
• Final Drive: Shaft drive
• Suspension Front: Independent double wishbone, 6.7" travel
• Suspension Rear: Independent swingarm, 7.1" travel
• Brakes: Dual hydraulic disc brakes front and rear
• Fuel Capacity: 2.6 gallons (10 liters)
• Oil Capacity: 2.1 quarts (2.0 liters) with filter change

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Engine Service

Proper engine maintenance is critical for performance.

1. Oil Change: Warm engine, drain oil, replace filter, refill with 2.1 quarts 10W-40 motorcycle oil.
2. Valve Clearance: Check every 1000 miles - intake 0.004-0.006 in, exhaust 0.006-0.008 in.
3. Carburetor: Clean every 500 miles or as needed, adjust idle speed 1400-1500 RPM.
4. Cooling: Keep fins clean for proper air cooling.
5. Spark Plug: NGK DR8ES, gap 0.028-0.031 in.

CAUTION! Engine must be cool before servicing. Use proper tools and torque specifications.

Transmission & Drive System

5-speed transmission with reverse and shaft drive system.

1. Transmission Oil: Change every 1000 miles with 80W-90 gear oil.
2. Shifting: Use clutch for smooth gear changes. Pattern: 1-N-2-3-4-5-R.
3. Reverse: Push down on reverse lever, shift to R position.
4. Drive Shaft: Lubricate universal joints every 500 miles.
5. Clutch: Adjust free play at lever to 0.2-0.4 in.

Tip: Always come to complete stop before engaging reverse.

Suspension & Brakes

Independent suspension and hydraulic disc brakes.

1. Front Suspension: Double wishbone with 6.7" travel, preload adjustable.
2. Rear Suspension: Swingarm with 7.1" travel, preload and rebound adjustable.
3. Brake Fluid: DOT 4, check level monthly, replace annually.
4. Brake Pads: Replace when worn to 1mm thickness.
5. Tire Pressure: Front 3.5 psi, Rear 3.0 psi for normal riding.

WARNING! Test brakes before each ride. Never use automotive brake fluid.

Electrical System

12V DC system with CDI ignition and electric start.

Storage & Winterization

Proper storage prevents damage during extended non-use.

1. Fill fuel tank and add fuel stabilizer.
2. Change engine oil and filter.
3. Remove spark plug, add 1 teaspoon oil, crank engine, reinstall plug.
4. Clean entire ATV thoroughly.
5. Inflate tires to maximum pressure.
6. Store in dry, covered area with battery disconnected.

CAUTION! Do not store with fuel in carburetor - drain float bowl.

Troubleshooting

Service: For technical support contact Yamaha customer service or authorized dealer.