Contents

- GENERAL INFORMATION
  - DESCRIPTION
  - MACHINE IDENTIFICATION
  - IMPORTANT INFORMATION
  - CHECKING OF CONNECTION
  - SPECIAL TOOLS
  - CONTROL FUNCTIONS
  - FUEL AND ENGINE MIXING OIL
  - STARTING AND BREAK-IN
  - TORQUE-CHECK POINTS
  - CLEANING AND STORAGE
- SPECIFICATIONS
  - GENERAL SPECIFICATIONS
  - MAINTENANCE SPECIFICATIONS
  - GENERAL TORQUE SPECIFICATIONS
  - DEFINITION OF UNITS
  - CABLE ROUTING DIAGRAM
- REGULAR INSPECTION AND ADJUSTMENTS
  - MAINTENANCE INTERVALS
  - PRE-OPERATION INSPECTION AND MAINTENANCE
  - ENGINE
  - CHASSIS
  - ELECTRICAL
- ENGINE
  - SEAT,FUEL TANK AND SIDE COVERS
  - EXHAUST PIPE AND SILENCER
  - RADIATOR
  - CARBURETOR AND REED VALVE
  - CYLINDER HEAD,CYLINDER AND PISTON
  - CLUTCH AND PRIMARY DRIVEN GEAR
  - KICK AXLE,SHIFT SHAFT AND PRIMARY DRIVE GEAR
  - YPVS GOVERNOR
  - WATER PUMP
  - CDI MAGNETO
  - ENGINE REMOVAL
  - CRANKCASE AND CRANKSHAFT
  - TRANSMISSION,SHIFT CAM AND SHIFT FORK
- CHASSIS
  - FRONT WHEEL AND REAR WHEEL
  - FRONT BRAKE AND REAR BRAKE
  - FRONT FORK
  - HANDLEBAR
  - STEERING
  - SWINGARM
  - REAR SHOCK ABSORBER
- ELECTRICAL
  - ELECTRICAL COMPONENTS AND WIRING DIAGRAM
  - IGNITION SYSTEM
- TUNING
  - ENGINE
  - CHASSIS

Yamaha YZ125W1 2007 Owner's Manual

Pages 268

Year 2007

Language(s)

of 268

Yamaha YZ125W1 2007 Specification

The Yamaha YZ125W1 2007 is a high-performance motocross bike engineered for competitive racing and exceptional handling. Powered by a 124cc liquid-cooled, 2-stroke, single-cylinder engine, the YZ125W1 delivers robust power and quick acceleration, making it a formidable contender on the track. The engine features Yamaha's Power Valve System (YPVS), which enhances performance by optimizing exhaust port timing for improved power delivery across the RPM range.

The YZ125W1 boasts a lightweight chassis constructed from high-tensile steel, ensuring both durability and agility. This chassis design, combined with an advanced aluminum subframe, contributes to the bike’s excellent maneuverability and responsiveness. The suspension system includes fully adjustable KYB front forks with 48mm tubes and a KYB rear shock, providing superior damping and rebound characteristics to handle the rigors of motocross racing.

The braking system comprises hydraulic disc brakes with a 250mm front disc and a 245mm rear disc, offering reliable stopping power and precise control. The bike’s ergonomics are designed for rider comfort and control, featuring a grippy seat, wide foot pegs, and adjustable handlebar mounts. These elements ensure that riders can maintain optimal posture and control during intense racing conditions.

A 5-speed transmission with a multi-plate wet clutch provides smooth and reliable gear shifts, supporting the bike’s high-performance capabilities. The YZ125W1 also includes a high-capacity radiator with large cooling fins to manage engine temperature effectively, ensuring consistent performance even during prolonged use.

In summary, the Yamaha YZ125W1 2007 is a meticulously designed motocross bike that combines powerful engine performance, advanced suspension, and robust braking systems to deliver an exceptional riding experience for competitive racers. Its lightweight construction and ergonomic design further enhance its reputation as a top-tier motocross machine.

Yamaha YZ125W1 2007 F.A.Q.

What type of oil should I use for the Yamaha YZ125W1 2007?

Use a high-quality 2-stroke engine oil specifically designed for motorcycles. Yamaha recommends using their Yamalube 2-R for optimal performance.

How often should I change the transmission oil on my YZ125W1 2007?

Change the transmission oil every 10 hours of riding to ensure smooth shifting and prevent wear. Regular maintenance helps in extending the life of the transmission.

What is the correct spark plug gap for the YZ125W1 2007?

The correct spark plug gap for the Yamaha YZ125W1 2007 is 0.7 - 0.8 mm. It is essential to maintain this gap for optimal ignition performance.

How do I troubleshoot starting issues with my YZ125W1 2007?

First, check the fuel supply and ensure the fuel tap is on. Inspect the spark plug for fouling and correct gap. Additionally, verify that the air filter is clean and the carburetor is not clogged.

What is the recommended tire pressure for the Yamaha YZ125W1 2007?

The recommended tire pressure for the YZ125W1 2007 is approximately 15 psi for both front and rear tires. Adjust based on terrain and riding style.

How can I adjust the suspension on my YZ125W1 2007 for better performance?

To adjust the suspension, use the compression and rebound damping adjusters found on the forks and shock absorber. Tailor the settings based on your riding conditions and weight for improved handling.

What steps should I follow for winter storage of my YZ125W1 2007?

For winter storage, clean the bike thoroughly, drain the fuel system, lubricate all moving parts, remove the battery and keep it on a trickle charger, and cover the bike to protect it from dust and moisture.

How do I clean the air filter on my Yamaha YZ125W1 2007?

Remove the air filter from the bike, wash it with a suitable cleaner, rinse with water, and allow it to dry completely. Apply air filter oil evenly and reinstall it. Ensure there are no gaps for debris to enter.

What are common signs of a worn-out clutch on the YZ125W1 2007?

Signs of a worn-out clutch include difficulty in shifting gears, slipping during acceleration, and a noticeable change in the clutch lever feel. If these symptoms are present, inspect the clutch plates and springs.

How can I improve the fuel efficiency of my YZ125W1 2007?

To improve fuel efficiency, ensure regular maintenance including cleaning the air filter, maintaining correct tire pressure, and adjusting the carburetor for optimal air-fuel mixture. Avoid aggressive riding styles.