The 2002-2007 Honda CR250R is part of Honda's legendary two-stroke motocross lineup, renowned for its precise handling, reliable engineering, and competitive performance. Here’s a comprehensive overview:

General Overview

• Model Years: 2002-2007
• Category: Motocross / Off-road
• Engine Type: Two-stroke single-cylinder
• Reputation: Known for its durability, race-ready design, and precise handling, it was a favorite among serious motocross riders.

Engine and Performance

• Displacement: 249 cc
• Cooling System: Liquid-cooled for consistent performance in demanding conditions.
• Bore x Stroke: 66.4 mm x 72.0 mm
• Compression Ratio: 8.5:1
• Horsepower: Approximately 45 HP, depending on tuning and modifications.
• Fuel System: Keihin 38 mm PWK carburetor, optimized for throttle response.
• Power Valve: Honda’s RC (Revolutionary Controlled) Valve System for improved low- to mid-range torque without sacrificing top-end power.

Drivetrain

• Transmission: 5-speed manual gearbox, with ratios optimized for motocross tracks.
• Clutch: Multi-plate wet clutch, designed to handle high-revving two-stroke demands.

Chassis and Suspension

• Frame: Aluminum twin-spar frame introduced in 1997, further refined for better rigidity and lighter weight.
• Front Suspension:
  • Showa 47 mm inverted cartridge forks, fully adjustable for rebound and compression damping.
  • 12.2 inches of travel.
• Rear Suspension:
  • Honda’s Pro-Link system with a fully adjustable Showa shock.
  • 12.4 inches of travel.
• Handling: Famous for its quick and precise steering, making it excellent for tight motocross tracks.

Brakes and Wheels

• Front Brakes: Single 240 mm hydraulic disc with a twin-piston caliper for strong stopping power.
• Rear Brakes: Single 240 mm hydraulic disc with a single-piston caliper.
• Tires: 21-inch front and 19-inch rear, with motocross-specific knobby treads.

Dimensions and Weight

• Seat Height: 37.4 inches, standard for motocross bikes, suitable for taller riders.
• Ground Clearance: 13.8 inches, designed for off-road and track obstacles.
• Dry Weight: Approximately 213 lbs, making it lightweight and nimble.
• Fuel Capacity: 2.1 gallons, adequate for motocross races and practice sessions.

Key Updates (2002-2007)

1. 2002 Major Overhaul:
   • New engine cases and improved RC Valve for smoother power delivery.
   • Revised exhaust port timing for better mid-range performance.
   • Lighter weight components in the engine and chassis.
   • Upgraded suspension for better handling.
2. 2003-2004 Refinements:
   • Minor suspension tweaks for improved damping.
   • Slight adjustments to the power valve system for a broader powerband.
3. 2005-2007:
   • Honda focused on fine-tuning, with minor changes to improve reliability and reduce weight.
   • Cosmetic updates, including new graphics and color schemes.

Features

• Ergonomics: Narrow chassis and slim bodywork for excellent rider movement.
• Exhaust: Tuned expansion chamber for optimal two-stroke performance.
• Build Quality: Known for Honda's reliability and high-quality components.

Pros

• Lightweight and nimble, with excellent handling.
• Reliable and durable for a two-stroke motocross bike.
• Broad powerband for versatility in different track conditions.
• Robust aftermarket support for parts and performance upgrades.
• Easy to service and maintain, with simple two-stroke mechanics.

Cons

• Requires frequent maintenance, including regular top-end rebuilds, as with any high-performance two-stroke.
• Lacks the low-end grunt of four-stroke competitors, especially in tight or technical sections.
• Discontinued after 2007, making some OEM parts harder to source.

Riding Experience

• The CR250R is praised for its balance and precision. It thrives on motocross tracks with its quick handling and explosive mid- to top-end power.
• While it requires an experienced rider to handle the aggressive power delivery effectively, it is highly rewarding for those who can master it.

Legacy

• The Honda CR250R was one of the most competitive two-strokes in its class, battling rivals like the Yamaha YZ250 and KTM 250 SX.
• After its discontinuation in 2007, the CR250R gained legendary status among two-stroke enthusiasts and is now a collector's item.
• Many riders retrofit the CR250R engine into modern four-stroke frames (e.g., CRF450R frames) to create custom "CR250AF" builds.

If you’re restoring or maintaining a CR250R, the strong aftermarket community and abundance of performance parts make it relatively easy to keep these bikes in top condition. Its legendary status and exceptional performance ensure it remains a beloved part of motocross history.