Yamaha YFM400FWR Big Bear 4X4 2003 Owner's Manual

Yamaha YFM400FWR Big Bear 4X4 2003 manual cover

Pages 174

Year 2003

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Yamaha YFM400FWR Big Bear 4X4 2003 Specification

The Yamaha YFM400FWR Big Bear 4X4 2003 is a robust all-terrain vehicle known for its reliability and performance in diverse conditions. This ATV is powered by a 386cc, air-cooled, four-stroke single-cylinder engine, delivering consistent power and torque for a variety of off-road applications. The engine is paired with a five-speed manual transmission, including a reverse gear, which allows for precise control and maneuverability over challenging terrain.

The YFM400FWR features a full-time four-wheel-drive system, enhancing its capability to navigate through mud, sand, and rocky surfaces. Its suspension system is designed for durability and comfort, with independent double-wishbone front suspension and a swingarm rear suspension, both providing substantial travel to absorb shocks and maintain stability. The vehicle is equipped with front dual hydraulic disc brakes and a sealed rear drum brake, ensuring reliable stopping power in wet and dry conditions.

This model boasts a sturdy steel frame and a high ground clearance, making it well-suited for rugged environments. The fuel capacity of 3.8 gallons supports extended rides without frequent refueling. Ergonomically designed, the YFM400FWR includes a comfortable seat and handlebars, as well as a digital instrument panel that provides essential operational information at a glance.

Additional features include a front cargo rack with a 88-pound capacity and a rear cargo rack capable of carrying up to 176 pounds, making it practical for both recreational and utility purposes. The Yamaha YFM400FWR Big Bear 4X4 2003 is a versatile and dependable ATV that combines power, durability, and user-friendly design, catering to outdoor enthusiasts and professionals alike.

Yamaha YFM400FWR Big Bear 4X4 2003 F.A.Q.

What type of oil should be used for the 2003 Yamaha YFM400FWR Big Bear 4X4?

Use a high-quality 4-stroke engine oil of SAE 10W-30 or 20W-40 depending on the ambient temperature. Always ensure the oil meets the JASO MA standard for wet clutch performance.

How often should the air filter be cleaned or replaced?

Clean the air filter every 20-30 hours of operation or more frequently if riding in dusty conditions. Replace the air filter if it is damaged or excessively dirty.

What is the recommended tire pressure for the Yamaha Big Bear 4X4 2003?

The recommended tire pressure is 4.0 psi (27.6 kPa) for both the front and rear tires. Always check the pressure when the tires are cold.

How can I troubleshoot an electrical issue where the Big Bear does not start?

Check the battery connections for corrosion, ensure the battery is charged, inspect the main fuse, and examine the ignition switch and starter relay for faults.

What should I do if the Yamaha Big Bear 4X4 is overheating?

Ensure the radiator is not clogged with debris, check coolant levels, and inspect the radiator fan operation. Make sure the engine oil level is adequate.

How do I adjust the drive chain tension on the Yamaha Big Bear 4X4?

Loosen the rear axle nut, adjust the chain tensioners evenly on both sides until the chain has 1.2-1.6 inches (30-40 mm) of slack, then retighten the axle nut.

What is the procedure for replacing the spark plug on the Yamaha YFM400FWR Big Bear 4X4?

Remove the spark plug cap, use a spark plug socket to remove the old plug, check the gap on the new plug (0.8-0.9 mm or 0.031-0.035 inches), install the new plug, and reattach the cap.

How can I maintain the brakes on my 2003 Yamaha Big Bear 4X4?

Regularly check the brake fluid level, inspect brake pads for wear, and ensure that the brake lines are not leaking. Adjust the brake lever and pedal free play as necessary.

What is the correct battery maintenance procedure for the Yamaha Big Bear 4X4?

Regularly check the battery terminals for corrosion, ensure the electrolyte levels are adequate, and keep the battery charged when not in use to prolong its lifespan.

How do I store the Yamaha YFM400FWR Big Bear 4X4 for an extended period?

Clean the ATV thoroughly, change the oil, add fuel stabilizer, disconnect the battery, and store it in a dry, covered location. Elevate the tires to prevent flat spots.