The 2005-2007 Kawasaki KX250 is a two-stroke motocross bike known for its powerful engine, sharp handling, and competitive performance. As part of Kawasaki's storied KX lineup, this bike is a favorite among two-stroke enthusiasts for its blend of power, agility, and rugged design.

General Overview

• Category: Motocross / Off-road
• Production Years: 2005-2007 (final years for the KX250 two-stroke).
• Engine Type: Two-stroke single-cylinder
• Reputation: Highly regarded for its strong midrange and top-end power, as well as its durable construction.

Engine and Performance

• Displacement: 249 cc
• Cooling System: Liquid-cooled for consistent performance in high-stress conditions.
• Bore x Stroke: 66.4 mm x 72.0 mm
• Compression Ratio: Approximately 9.0:1.
• Carburetor: Keihin PWK 38 mm, providing crisp throttle response and efficient fueling.
• Horsepower: Approximately 46 HP, competitive with other two-stroke 250cc bikes.
• Power Valve: Kawasaki Integrated Power Valve System (KIPS), enhancing low- to mid-range torque while maintaining strong top-end power.
• Powerband: Broad and aggressive, excelling in mid-to-high RPMs, ideal for motocross tracks and open terrain.

Drivetrain

• Transmission: 5-speed manual gearbox, optimized for racing conditions.
• Clutch: Multi-plate wet clutch for smooth engagement and reliability under heavy use.
• Final Drive: Chain drive, standard for motocross bikes.

Chassis and Suspension

• Frame: High-tensile steel perimeter frame, designed for a balance of rigidity and flex, offering stability and precise handling.
• Front Suspension:
  • Kayaba (KYB) 48 mm inverted forks.
  • Fully adjustable for compression and rebound damping.
  • Travel: Approximately 12.4 inches.
• Rear Suspension:
  • Kawasaki’s Uni-Trak linkage system with a KYB shock.
  • Fully adjustable for preload, rebound, and compression damping.
  • Travel: Around 12.2 inches.
• Handling: Known for its quick and precise handling, with a planted feel in corners and excellent high-speed stability.

Brakes and Wheels

• Front Brakes: Single 250 mm hydraulic disc brake with a dual-piston caliper for strong stopping power.
• Rear Brakes: Single 240 mm hydraulic disc brake with a single-piston caliper.
• Tires: 21-inch front and 19-inch rear knobby tires, optimized for motocross tracks.

Dimensions and Weight

• Seat Height: Approximately 37.6 inches, standard for motocross bikes.
• Ground Clearance: Around 13.4 inches, ideal for handling jumps and rough terrain.
• Dry Weight: Approximately 213 lbs, making it competitive in its class.
• Fuel Capacity: 2.1 gallons, typical for motocross bikes.

Key Updates

1. 2005:
   • Introduction of a new steel perimeter frame for improved handling and durability.
   • Revised engine porting and KIPS tuning for enhanced power delivery.
   • Improved suspension settings for better control in varied track conditions.
2. 2006:
   • Updated ergonomics, including slimmer bodywork for improved rider mobility.
   • Suspension refinements for a smoother ride and better bottoming resistance.
3. 2007:
   • Minor engine and suspension tweaks.
   • New graphics and styling updates, marking the final year of production for the two-stroke KX250.

Features

• Durability: Built to withstand the rigors of motocross racing, with a reputation for reliability.
• Ergonomics: Slim design and comfortable seat height for aggressive riding.
• Power Delivery: Strong and predictable powerband, suitable for both intermediate and advanced riders.
• Aftermarket Support: Extensive options for parts and performance upgrades.

Pros

• Strong, broad powerband with excellent top-end performance.
• Lightweight and nimble handling, ideal for motocross tracks.
• Durable and reliable with proper maintenance.
• High-quality suspension for tackling rough terrain and jumps.
• Simple two-stroke design makes it easy to rebuild and maintain.

Cons

• Requires frequent maintenance, including top-end rebuilds typical of two-stroke engines.
• Vibrations can be noticeable at high RPMs.
• Lacks the low-end torque of modern four-stroke bikes.
• Discontinued after 2007, making OEM parts less available over time.

Riding Experience

• The KX250 offers a thrilling ride with its powerful engine and quick handling.
• It shines on motocross tracks, with strong acceleration, smooth cornering, and excellent performance over jumps.
• While it requires a skilled rider to fully utilize its aggressive powerband, it remains forgiving enough for intermediate riders.

Legacy

• The 2005-2007 Kawasaki KX250 marked the end of Kawasaki’s two-stroke dominance in the motocross world as the industry shifted toward four-stroke engines.
• It remains a beloved bike among two-stroke enthusiasts and collectors, praised for its performance, durability, and nostalgic appeal.
• The KX250 is still commonly used in vintage and amateur motocross racing due to its competitive edge and strong aftermarket support.

If you’re considering or maintaining a 2005-2007 Kawasaki KX250, you’re investing in a legendary machine with a rich motocross heritage. With proper care and modern upgrades, the KX250 continues to deliver an exhilarating and competitive riding experience.