Yamaha YZ250S 2004 Owner's Manual

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Year 2004

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Yamaha YZ250S 2004 Specification

The 2004 Yamaha YZ250S is a high-performance motocross motorcycle engineered for competitive racing and advanced off-road capabilities. It features a liquid-cooled, 249cc, 2-stroke, single-cylinder engine designed for optimal power delivery and responsiveness. The engine's reed-valve induction system ensures efficient fuel mixture and combustion, while the Keihin PWK38S carburetor provides precise throttle control. Transmission is managed through a 5-speed gearbox, allowing for smooth gear transitions during aggressive riding.

A lightweight aluminum frame contributes to the bike's agility and handling precision, making it highly responsive on varied terrains. The suspension system is composed of fully adjustable KYB forks in the front and a KYB mono-shock in the rear, offering a customizable and smooth ride over rough surfaces. Braking performance is assured by hydraulic disc brakes on both the front and rear, providing reliable stopping power.

The YZ250S is equipped with a 2.1-gallon fuel tank that balances capacity with weight distribution for extended riding sessions. Its overall weight of approximately 212 pounds enhances maneuverability without compromising stability. The bike's ergonomics are designed for rider comfort and control, featuring a narrow seat and optimized handlebar positioning.

Tire specifications include a 21-inch front and 19-inch rear, both fitted with aggressive tread patterns to maximize traction. The YZ250S's aesthetic is marked by Yamaha’s signature blue and white color scheme, combined with durable plastics that withstand the rigors of off-road riding. Overall, the 2004 Yamaha YZ250S stands out as a robust and agile motocross bike, ideal for both professional racers and serious enthusiasts.

Yamaha YZ250S 2004 F.A.Q.

What is the recommended spark plug for the Yamaha YZ250S 2004?

The recommended spark plug for the Yamaha YZ250S 2004 is the NGK BR8EG. Ensure it is properly gapped according to the manufacturer's specifications before installation.

How often should I change the transmission oil in my Yamaha YZ250S 2004?

It's recommended to change the transmission oil every 10 hours of riding or after every race. This helps maintain optimal performance and prolongs the life of the transmission components.

What is the correct chain tension for the Yamaha YZ250S 2004?

Adjust the chain tension so that there's approximately 1.2 to 1.6 inches (30 to 40 mm) of slack at the center of the chain when measured from the top of the swingarm.

How do I troubleshoot starting problems with my Yamaha YZ250S 2004?

Check the spark plug for fouling, ensure there is fresh fuel in the tank, inspect the air filter for cleanliness, and verify that the carburetor is not clogged or leaking.

What type of coolant should be used in the Yamaha YZ250S 2004?

Use a high-quality ethylene glycol-based coolant mixed with distilled water in a 50/50 ratio. Make sure it is suitable for aluminum engines to prevent corrosion.

How can I improve the suspension performance on my Yamaha YZ250S 2004?

Adjust the fork and shock settings according to your weight and riding style. Consider upgrading to aftermarket suspension components for enhanced performance. Regular maintenance like oil changes also helps maintain efficiency.

What is the recommended tire pressure for the Yamaha YZ250S 2004?

For general off-road riding, the recommended tire pressure is 12-15 psi. Adjust based on terrain and rider preference for optimal traction and comfort.

How do I adjust the clutch on my Yamaha YZ250S 2004?

To adjust the clutch, locate the clutch cable adjuster on the handlebar. Turn the adjuster to achieve approximately 1/8 inch (3 mm) of free play at the lever. Ensure smooth operation without slipping.

What should I do if my Yamaha YZ250S 2004 is overheating?

Check the coolant level and ensure there are no leaks. Clean the radiator fins from debris. Consider installing a higher pressure radiator cap or aftermarket cooling solutions if overheating persists.

How do I store my Yamaha YZ250S 2004 for the winter?

Clean the bike thoroughly, drain the fuel system or use a fuel stabilizer, lubricate all moving parts, and store it in a dry, covered area. Disconnect the battery and consider elevating the bike to prevent tire flat spots.