Yamaha YFM400R Big Bear 2003 Owner's Manual

Yamaha YFM400R Big Bear 2003 manual cover

Pages 172

Year 2003

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Yamaha YFM400R Big Bear 2003 Specification

The 2003 Yamaha YFM400R Big Bear is an all-terrain vehicle (ATV) designed for both utility and recreational use. This ATV is powered by a 386cc, air-cooled, 4-stroke, single-cylinder engine that delivers reliable performance across various terrains. The engine is paired with a 5-speed manual transmission, which includes a reverse gear, providing versatility and control in diverse riding conditions. The YFM400R features an electric start system, complemented by a backup recoil starter for added convenience and reliability.

The chassis is built with a durable steel frame that ensures robustness and stability, making it suitable for rugged environments. The front suspension consists of an independent double-wishbone system with 5.8 inches of travel, while the rear suspension uses a swingarm setup with 6.3 inches of travel, both designed to absorb shocks and provide a smooth ride. The braking system is comprised of dual hydraulic front disc brakes and a sealed drum brake at the rear, offering dependable stopping power.

The ATV rides on 25-inch tires mounted on durable steel wheels, enhancing its capability to navigate through challenging landscapes. With a ground clearance of 9.7 inches and a wheelbase of 48.8 inches, the YFM400R provides excellent stability and maneuverability. The fuel tank has a capacity of 3.8 gallons, allowing for extended rides without frequent refueling.

Additional features include a front cargo rack with a capacity of 88 pounds and a rear cargo rack capable of carrying up to 176 pounds, making it ideal for carrying tools, supplies, or recreational gear. The Yamaha YFM400R Big Bear 2003 combines robust engineering with practical features, making it a versatile choice for a wide range of outdoor activities.

Yamaha YFM400R Big Bear 2003 F.A.Q.

What type of oil should be used for the Yamaha YFM400R Big Bear 2003?

For the Yamaha YFM400R Big Bear 2003, it is recommended to use 10W-40 4-stroke motorcycle oil for optimal engine performance and protection.

How often should I change the oil in my Yamaha YFM400R Big Bear 2003?

It is recommended to change the oil every 20 hours of operation or every 1,000 miles, whichever comes first, to ensure engine longevity and reliability.

What is the proper way to adjust the drive chain on the Yamaha YFM400R Big Bear 2003?

To adjust the drive chain, first, place the ATV on a level surface. Loosen the axle nut, adjust the chain tension using the adjuster bolts until there is approximately 1-1.5 inches of slack in the chain, and retighten the axle nut securely.

What should I check if my Yamaha YFM400R Big Bear 2003 is having trouble starting?

If your ATV is having trouble starting, check the battery charge, ensure that the fuel is fresh and sufficient, inspect the spark plug for wear or fouling, and verify that the kill switch is in the correct position.

How do I clean the air filter on the Yamaha YFM400R Big Bear 2003?

Remove the air filter cover and take out the air filter. Wash the filter with warm, soapy water and rinse thoroughly. Allow it to dry completely before applying a thin layer of air filter oil and reinstalling it.

What is the recommended tire pressure for the Yamaha YFM400R Big Bear 2003?

The recommended tire pressure for the Yamaha YFM400R Big Bear 2003 is 4 psi for the front tires and 4 psi for the rear tires. Always check the tire pressure when the tires are cold.

How do I troubleshoot electrical issues on my Yamaha YFM400R Big Bear 2003?

Begin by checking the battery connections and ensuring they are tight and free of corrosion. Inspect fuses and replace any that are blown. Examine wiring for any visible damage or loose connections.

What maintenance should be performed before storing the Yamaha YFM400R Big Bear 2003 for an extended period?

Before storing the ATV, perform an oil change, fill the fuel tank and add a fuel stabilizer, clean and lubricate the chain, inflate tires to the recommended pressure, and disconnect the battery to prevent discharge.

How can I improve the fuel efficiency of my Yamaha YFM400R Big Bear 2003?

To improve fuel efficiency, ensure regular maintenance such as keeping the air filter clean, maintaining proper tire pressure, and using the recommended grade of oil. Avoid aggressive riding and carry only necessary weight.

What should I do if the Yamaha YFM400R Big Bear 2003 is overheating?

If the ATV is overheating, check for obstructions in the cooling fins, ensure the radiator is free from debris, verify the coolant level is appropriate, and inspect the fan for proper operation.