Yamaha Grizzly 90 Owners Manual

The Yamaha Grizzly 90 is a youth ATV (All-Terrain Vehicle) designed for riders aged 10 and older. It features a 90cc 4-stroke engine, automatic transmission with reverse, electric start, independent rear suspension, front disc brake, rear drum brake, and a durable steel frame. This manual covers safety, operation, maintenance, specifications, and troubleshooting for the Grizzly 90. Always read and understand this manual before operating the vehicle.

Features at a Glance

Key components: 90cc 4-stroke engine, Automatic CVT transmission with reverse, Electric start, Independent rear suspension, Front disc brake, Steel frame, Speed limiter, Towing hitch (optional).

Safety Information

Always wear appropriate safety gear. This ATV is for off-road use only by riders aged 10 and older.

1. Always wear a helmet, eye protection, gloves, long sleeves, long pants, and over-the-ankle boots.
2. Never carry passengers. The Grizzly 90 is designed for one rider only.
3. Ride only on designated trails and areas where ATV use is permitted.
4. Never operate under the influence of alcohol or drugs.
5. Complete a training course. Supervise riders under 16.

WARNING! Failure to follow safety instructions can result in serious injury or death. The ATV can handle differently than other vehicles. Practice in a safe, open area.

Controls and Instruments

Familiarize yourself with all controls before starting the engine.

1. Ignition Switch: ON/OFF and start position.
2. Engine Stop Switch: Cuts ignition; set to RUN to start.
3. Throttle Lever: Right handlebar. Release to idle.
4. Brake Lever: Front brake on right handlebar.
5. Brake Pedal: Rear brake on right footrest.
6. Drive Select Lever: F (Forward), N (Neutral), R (Reverse).
7. Speed Limiter Screw: Under seat; adjusts maximum speed.
8. Fuel Valve: Under fuel tank; ON, OFF, RES.
9. Choke Knob: For cold starting.

CAUTION! Understand function of all controls. Practice braking and throttle control before riding.

Pre-Ride Inspection

Perform this check before every ride.

• Fuel: Check level. Use unleaded gasoline (87 octane or higher).
• Oil: Check engine oil level with dipstick on level ground.
• Tires: Inspect for damage, check pressure (Front: 3.6 psi, Rear: 3.6 psi).
• Brakes: Test front lever and rear pedal for proper operation.
• Throttle: Ensure lever moves smoothly and returns automatically.
• Drive Chain: Check tension and lubrication.
• Lights: Check headlight and taillight (if equipped).
• Nuts & Bolts: Ensure critical fasteners are tight.

Starting and Operating

Starting Procedure (Electric Start):

1. Place ATV on level surface. Set Drive Select Lever to N (Neutral).
2. Turn Fuel Valve to ON.
3. Turn Ignition Switch to ON. Set Engine Stop Switch to RUN.
4. For cold engine, pull Choke Knob out fully.
5. Press and hold brake lever. Press START button.
6. After engine starts, push Choke Knob in gradually as engine warms.

Riding:

1. Mount ATV, keeping weight centered.
2. With engine running and brakes applied, select F (Forward).
3. Release brakes and apply throttle gradually to move forward.
4. To reverse: Come to complete stop. Select R (Reverse). Apply throttle slowly.
5. Always use both brakes for controlled stopping.

Tip: Avoid full-throttle starts and sudden braking. Learn on flat, open terrain.

Maintenance Schedule

Regular maintenance ensures safety and longevity. Refer to manual for detailed intervals.

Specifications

• Model: Yamaha Grizzly 90 (YFM90)
• Engine Type: 4-stroke, SOHC, air-cooled
• Displacement: 90cc
• Bore x Stroke: 47.0 x 52.0 mm
• Compression Ratio: 9.5:1
• Starting System: Electric & Recoil
• Transmission: Automatic V-belt CVT, F-N-R
• Final Drive: Chain
• Suspension Front/Rear: Independent / Independent
• Brakes Front/Rear: Disc / Drum
• Tires Front/Rear: AT19 x 7-8 / AT18 x 9.5-8
• L x W x H: 64.4 x 40.2 x 40.0 in
• Seat Height: 25.0 in
• Ground Clearance: 4.3 in
• Fuel Capacity: 1.6 gal
• Curb Weight: 278 lbs

Basic Maintenance Procedures

Engine Oil Change:

1. Run engine to warm oil. Place ATV on level surface.
2. Remove drain plug and oil filler cap. Drain oil into pan.
3. Replace drain plug washer, tighten plug.
4. Refill with recommended SAE 10W-30 oil (approx. 1.1 qt). Check level with dipstick.

Air Filter Service:

1. Remove seat and air filter cover.
2. Remove foam filter. Wash in warm, soapy water. Rinse and dry completely.
3. Apply filter oil evenly. Reinstall.

Drive Chain Adjustment:

1. Check slack (1.0-1.4 in). Loosen axle nut and adjuster locknuts.
2. Turn adjusters equally to achieve proper slack. Tighten locknuts and axle nut.
3. Lubricate chain with chain lube.

Storage

If storing for more than 30 days:

1. Change engine oil and filter.
2. Add fuel stabilizer to full gas tank. Run engine for 10 minutes.
3. Turn fuel valve to OFF. Drain carburetor float bowl if equipped.
4. Remove spark plug, add a teaspoon of oil, crank engine, reinstall plug.
5. Clean ATV thoroughly. Inflate tires to recommended pressure.
6. Store in cool, dry place. Use a breathable cover.
7. Disconnect battery negative terminal if equipped with battery.

CAUTION! Gasoline left in system can degrade and cause starting problems.

Troubleshooting

Reset: For electronic issues, disconnect battery for 5 minutes (if equipped).

Service: For complex repairs, see an authorized Yamaha dealer.

Warranty & Support

Yamaha Limited Warranty: 6 months for Grizzly 90. Proof of purchase required. Does not cover normal wear, improper maintenance, or accidents. Always use genuine Yamaha parts.

For support, contact an authorized Yamaha ATV dealer or visit www.yamahamotorsports.com. Keep this manual with the ATV.