While uncommon, some items may ship from a separate warehouse

About the Clutch Cover

Features
Set your ride apart from the rest with the ultimate look in race performance
Lightweight factory clutch covers provide years of outstanding protection; guaranteed not to warp
Individually surfaced for a perfect, leak-free fit
Super-tough, powder-coated finish resists weathering and wear and tear
Asbestos-free gasket is bound with nitrile for tight, leak-free seal

About the Ignition Cover

Features
Look like a professional with the Factory Ignition Cover
Seals properly, guarding inside of engine from dirt and water and outlasts stock covers
Boyesen Factory Covers are cast from the highest grade of aluminum and are strong yet lightweight
Super-tough, powder-coated finish resists weathering and wear and tear

About the 1999-2018 Yamaha YZ250

The 1999–2018 Yamaha YZ250 is widely regarded as one of the most iconic and respected two-stroke motocross bikes ever produced. Its nearly two-decade run with minimal fundamental changes is a testament to Yamaha’s exceptional original design, proven durability, competitive performance, and ongoing popularity among enthusiasts and racers alike.

Here's a comprehensive overview of the 1999–2018 Yamaha YZ250:

---

Overview and Historical Context:

Introduced in its modern form in 1999, the Yamaha YZ250 underwent significant updates that year, forming the foundation of a motocross bike that would remain largely unchanged for nearly two decades. Yamaha’s "if it’s not broken, don’t fix it" philosophy was well justified, as the bike’s combination of power, reliability, handling, and ease of maintenance became legendary.

While competitors moved toward four-stroke bikes and new technology, Yamaha maintained the YZ250 as a staple in their lineup, continually refining it through small adjustments rather than radical overhauls. The YZ250 remains highly popular in both amateur motocross and off-road racing circuits today.

---

Engine & Performance:

• Engine Specifications:

  • 249cc liquid-cooled two-stroke, single-cylinder
  • Yamaha Power Valve System (YPVS), ensuring smooth, strong, controllable power delivery
  • Reed-valve intake (V-Force reeds often added as aftermarket upgrades)
  • 5-speed close-ratio gearbox

• Performance Characteristics:

  • Renowned for broad, user-friendly power delivery with exceptional mid-range torque and strong top-end performance.
  • Responsive throttle feel with minimal vibration and remarkable reliability.
  • Ease of tuning and relatively simple maintenance have made it a favorite among riders and racers alike.

---

Chassis, Suspension, and Handling:

• Frame & Chassis:

  • Lightweight aluminum frame introduced in 2005, dramatically improving handling, agility, and rigidity.
  • 1999–2004 models featured a lightweight steel frame, highly praised for balance and predictable handling.
  • Stable and precise, suitable for a wide range of skill levels and riding styles.

• Suspension Components:

  • KYB Speed-Sensitive System (SSS) forks from 2006 onward, widely regarded as some of the best production motocross forks ever made.
  • KYB fully adjustable rear shock paired with Yamaha’s linkage system (YZ Pro-Link).
  • Consistent praise for plush, controlled action, superior to most contemporary offerings.

• Braking System:

  • Reliable hydraulic disc brakes front and rear (Nissin components), consistently good stopping power and modulation.

---

Evolution by Year Group:

1999–2004 (Steel-Frame Era):

• 1999: Major redesign; updated engine design, suspension refinements, improved ergonomics.
• Continued incremental improvements to suspension, carburetion, and ergonomics throughout early 2000s.

2005–2018 (Aluminum-Frame Era):

• 2005: Major chassis redesign introducing aluminum perimeter frame, significantly improving handling and weight reduction.
• 2006: Introduction of the acclaimed KYB SSS front forks, dramatically enhancing suspension performance.
• 2007–2014: Incremental refinements in ergonomics, graphics, suspension settings, and minor carburetion improvements.
• 2015–2018: Updated styling with more modern plastic bodywork, improved ergonomics and aesthetics, and small suspension refinements. Engine largely unchanged due to proven reliability and performance.

---

Racing Legacy and Popularity:

• The YZ250 has long been a favorite of amateur motocross racers due to its low cost of ownership, competitive power, and unmatched reliability.
• Popular in GNCC, Enduro, and desert racing circuits due to its versatility and easy maintenance.
• Notably used by many veteran racers and weekend enthusiasts for recreational riding, vet-class racing, and nostalgia racing events.

---

Collectibility and Market Appeal:

YZ250 models from the aluminum-frame era (2005–2018) are especially desirable due to their modern chassis and advanced suspension. The bike remains a top pick for restorations, customization, and competitive racing builds.

• Most Collectible Models:

  • 2005 (first aluminum-frame)
  • 2006 (first KYB SSS forks)
  • 2015–2018 (latest cosmetic upgrades)

• Parts Availability:
  Exceptional OEM and aftermarket support makes rebuilding or maintaining these bikes very straightforward.

---

Common Maintenance and Issues:

• YPVS Power Valve Maintenance:
  Routine cleaning is necessary (recommended every 20-30 hours of riding).

• Top-End Rebuild:
  Suggested every 50-60 hours for recreational use; shorter intervals (30-40 hours) for competition-level riding.

• Suspension Service:
  Regular fork seal and oil replacement, shock oil, and linkage bearings maintenance recommended annually or every 30-50 riding hours.

• Carburetion and Jetting:
  The stock Mikuni TMX carburetor occasionally requires jetting adjustments for optimal throttle response, especially at altitude or temperature extremes.

---

Conclusion:

The 1999–2018 Yamaha YZ250 stands as one of the motocross world’s most iconic and beloved machines. Its long-lasting production, excellent performance, unmatched reliability, and legendary suspension earned it universal acclaim from professionals, amateurs, and enthusiasts.

Today, the YZ250 is still a top choice for riders seeking simplicity, affordability, and the raw excitement that only a classic two-stroke motocross bike can deliver.