The 1986-2001 Honda CR250R is one of the most influential dirt bikes in motocross history, evolving over these years to remain a competitive choice for riders. Here’s a detailed breakdown of this iconic two-stroke motocross machine:

General Overview

• Model Years: 1986-2001
• Category: Motocross / Off-road
• Engine Type: Two-stroke single-cylinder
• Reputation: Known for its balance of power, handling, and Honda’s legendary reliability, the CR250R was a staple in motocross racing during its production years.

Engine and Performance

• Displacement: 249 cc
• Cooling System: Liquid-cooled from the start, ensuring consistent performance in high-stress conditions.
• Bore x Stroke: 66.4 mm x 72.0 mm
• Compression Ratio: Varied slightly across model years but typically around 8.5:1.
• Fuel System: Keihin carburetors (e.g., PJ or PWK series), optimized for sharp throttle response.
• Horsepower: Approximately 40-45 HP, depending on year and tuning.
• Power Valve: The introduction of Honda’s ATAC (Automatic Torque Amplification Chamber) in earlier years, replaced by the Honda RC Valve (Revolutionary Controlled Valve) in 1992, which improved low- to mid-range torque.

Drivetrain

• Transmission: 5-speed manual gearbox, designed for a wide range of motocross conditions.
• Clutch: Multi-plate wet clutch, offering consistent performance under high loads.

Chassis and Suspension

• Frame:
  • 1986-1996: Steel frame.
  • 1997 onwards: Aluminum twin-spar frame, introduced for weight reduction and improved rigidity.
• Front Suspension:
  • Early years: Conventional telescopic forks.
  • 1989 onwards: Showa inverted cartridge forks with increasing adjustability.
  • Later years: Fully adjustable Showa forks with 12.2 inches of travel.
• Rear Suspension:
  • Honda’s Pro-Link system, offering 12.4 inches of travel, continuously refined for improved damping and adjustability.

Brakes and Wheels

• Front Brakes: Hydraulic disc brakes introduced early on for consistent stopping power.
• Rear Brakes:
  • 1986-1987: Drum brake.
  • 1988 onwards: Hydraulic disc for improved performance.
• Tires: 21-inch front and 19-inch rear, with motocross-specific knobby treads.

Dimensions and Weight

• Seat Height: Approximately 37.5 inches, standard for motocross bikes.
• Ground Clearance: Around 13.8 inches, ideal for off-road and track obstacles.
• Weight:
  • 1986-1996: Approximately 225 lbs (dry).
  • 1997 onwards: Around 213 lbs (dry), thanks to the lighter aluminum frame.
• Fuel Capacity: 2.1 gallons, suitable for races and practice sessions.

Notable Updates by Model Year

1. 1986:
   • Featured Honda’s ATAC power valve system, offering better torque at low RPMs.
   • Introduced liquid cooling for improved engine reliability and consistency.
2. 1989:
   • First model to use inverted forks, enhancing handling and front-end stability.
3. 1992:
   • Introduction of the RC Valve system, replacing ATAC for more linear and refined power delivery.
4. 1997:
   • Major redesign with an aluminum twin-spar frame, reducing weight and increasing rigidity.
5. 1999-2001:
   • Continued refinements to suspension, ergonomics, and minor engine tweaks for smoother power delivery and better handling.

Features

• Ergonomics: Slim and compact design, allowing easy rider movement.
• Exhaust: Tuned expansion chambers for optimal two-stroke performance.
• Build Quality: Honda's reputation for durability and reliability shines through, even under demanding motocross conditions.

Pros

• Lightweight and nimble, offering excellent handling.
• Reliable and durable, even with the high stresses of motocross racing.
• Smooth and powerful two-stroke engine, with a strong mid- to top-end powerband.
• Strong aftermarket support for parts and upgrades.
• Easy to maintain and service compared to four-stroke competitors.

Cons

• Requires regular maintenance, including top-end rebuilds typical of two-strokes.
• The aggressive power delivery can be intimidating for less experienced riders.
• Older models (pre-1997) are heavier due to the steel frame.
• Suspension, while advanced for its time, is outdated by modern standards.
• Discontinued after 2007, making some OEM parts for earlier models scarce.

Riding Experience

• The CR250R excels in motocross environments, where its lightweight frame and responsive engine can be fully utilized.
• Its aggressive power delivery demands a skilled rider but rewards with exceptional performance in experienced hands.
• Quick handling and high-speed stability make it a favorite for tight tracks and jumps.

Legacy

• The CR250R dominated motocross racing during its peak years, competing with other legendary two-strokes like the Yamaha YZ250 and Suzuki RM250.
• It remains a cult favorite among two-stroke enthusiasts and collectors, with many considering it one of the best dirt bikes Honda ever produced.
• The 1997 aluminum frame marked a significant turning point, influencing the design of modern motocross bikes.
• The CR250R is still sought after for custom builds, including hybrids where the two-stroke engine is transplanted into modern four-stroke frames.

If you're restoring or maintaining a 1986-2001 CR250R, the strong aftermarket community and wealth of available parts make it a viable and rewarding project. Its reputation as a durable, high-performance motocross machine ensures its place in off-road history.