2020-2023 Yamaha YZ125X

The YZ125X is Yamaha’s two-stroke cross-country variation of the legendary YZ125 motocross bike. It’s purpose-built for off-road racing and trail riding, offering a more forgiving power delivery and tailored features for technical terrain.

Specifications

• Category: Cross-Country / Off-road
• Engine:
  • Type: Liquid-cooled, two-stroke, single-cylinder.
  • Displacement: 125 cc.
  • Bore x Stroke: 54.0 mm x 54.5 mm.
  • Compression Ratio: 7.4~8.8:1.
  • Carburetor: Mikuni TMX38, tuned for smoother power delivery.
  • Power Valve: Yamaha Power Valve System (YPVS), broadening the powerband.
• Transmission: 6-speed manual, wide-ratio gearbox tailored for off-road versatility.
• Starter: Kickstart.

Chassis and Suspension

• Frame: Aluminum bilateral beam, offering a balance of rigidity and flex for off-road performance.
• Front Suspension:
  • KYB 48 mm inverted forks, fully adjustable.
  • Travel: 11.8 inches.
• Rear Suspension:
  • KYB Monocross shock with a linkage system.
  • Travel: 12.4 inches.
• Brakes:
  • Front: 270 mm hydraulic disc.
  • Rear: 240 mm hydraulic disc.
• Tires: 18-inch rear wheel for better traction and cushioned off-road performance, 21-inch front.

Key Features

1. Off-Road Tuning:
   • The engine is detuned slightly compared to the YZ125 motocross bike for smoother, more controllable power delivery.
   • Wide-ratio transmission allows for better low-speed crawling and high-speed cruising.
2. Enduro Enhancements:
   • Off-road-specific suspension settings for tackling rough trails.
   • Larger rear sprocket for better climbing capabilities.
   • Includes a kickstand and 18-inch rear wheel for trail riding.
3. Lightweight Design:
   • Approximately 209 lbs (wet), making it nimble and easy to handle in tight or technical terrain.

Riding Experience

• The YZ125X is perfect for riders who want a lightweight, agile bike for cross-country or enduro racing.
• Its smooth power delivery and excellent suspension make it forgiving for intermediate riders while providing enough performance for advanced riders.

2005-2023 Yamaha YZ125

The YZ125 is Yamaha’s legendary two-stroke motocross bike, renowned for its explosive powerband, nimble handling, and race-ready performance. It has been a staple in the 125cc class for decades, frequently updated to stay competitive.

Specifications

• Category: Motocross / Off-road
• Engine:
  • Type: Liquid-cooled, two-stroke, single-cylinder.
  • Displacement: 125 cc.
  • Bore x Stroke: 54.0 mm x 54.5 mm.
  • Compression Ratio: 8.6:1.
  • Carburetor:
    • 2005-2021: Mikuni TMX38.
    • 2022 onward: Keihin PWK38S, offering improved throttle response and fuel delivery.
  • Power Valve: Yamaha Power Valve System (YPVS) for broader power delivery.
• Transmission: 6-speed manual gearbox.
• Starter: Kickstart.

Chassis and Suspension

• Frame:
  • 2005-2021: Aluminum bilateral beam frame for rigidity and lightweight handling.
  • 2022-2023: Updated frame geometry and ergonomics for enhanced cornering and stability.
• Front Suspension:
  • KYB 48 mm inverted forks, fully adjustable.
  • Travel: 11.8 inches.
• Rear Suspension:
  • KYB Monocross shock with a linkage system.
  • Travel: 12.4 inches.
• Brakes:
  • Front: 270 mm hydraulic disc.
  • Rear: 240 mm hydraulic disc.
• Tires: 21-inch front and 19-inch rear for motocross-specific performance.

Key Features

1. High-Performance Engine:
   • Aggressive mid-to-top-end powerband, ideal for motocross racing.
   • Lighter components and improved airflow (post-2022) for better acceleration.
2. Modern Updates:
   • The 2022 model introduced redesigned bodywork for a slimmer, more ergonomic feel.
   • Updated Keihin carburetor and intake system for smoother throttle response.
3. Lightweight Handling:
   • Approximately 209 lbs (wet), making it one of the lightest bikes in its class.

Riding Experience

• The YZ125 is an exhilarating motocross bike with a power delivery that rewards aggressive riders.
• Its nimble handling and explosive acceleration make it perfect for tight tracks, jumps, and competitive racing.
• While it’s best suited for intermediate to advanced riders, beginners with motocross ambitions also find it an excellent learning platform.

Comparison: YZ125X vs. YZ125

Legacy

1. YZ125:
   • A cornerstone of motocross racing, with decades of refinement and championships.
   • Beloved by riders for its lightweight, explosive performance, and easy maintenance.
2. YZ125X:
   • A successful adaptation of the YZ125 for off-road and cross-country use.
   • Praised for its versatility and trail-specific tuning.

Both bikes remain top choices for riders seeking two-stroke performance, with the YZ125 excelling on the track and the YZ125X dominating trails and technical terrain.