2005 Honda CRF250R
General Specifications
| Model | Honda CRF250R |
| Year | 2005 |
| Category | Motocross |
| Engine Type | 249 cc single-cylinder, four-stroke, liquid-cooled, SOHC Unicam, 4-valve |
| Weight | 92.5 kg dry |
Engine
| Displacement | 249 cc |
| Bore x Stroke | 78.0 x 52.2 mm |
| Compression Ratio | 12.5:1 |
| Fuel System | Keihin 37 mm FCR flat-slide carburettor with throttle position sensor | Replacement Options |
| Ignition | CDI with electronic advance |
| Spark Plug | NGK R0409B-8 |
| Spark Plug Gap | 0.6-0.7 mm |
| Cooling System | Liquid-cooled |
| Starting System | Primary kick starter with automatic decompression and hot-start system |
Transmission
| Transmission | Close-ratio 5-speed |
| Clutch | Wet multi-plate, 8-disc |
| Final Drive | #520 chain; 13/51 gearing |
Dimensions
| Overall Length | |
| Overall Width | |
| Overall Height | |
| Wheelbase | 1,478 mm |
| Ground Clearance | 361 mm |
| Seat Height | 965 mm |
| Fuel Capacity | 7.6 L |
Chassis
| Frame | Fourth-generation aluminium twin-spar motocross frame with aluminium swingarm |
| Front Tyre | 80/100-21 51M | Tyre Size Guide |
| Rear Tyre | 100/90-19 57M | Tyre Size Guide |
Suspension
| Front Suspension | 47 mm Showa inverted twin-chamber cartridge fork, 16-position compression and 16-position rebound adjustment | Fork Oil Levels |
| Front Suspension Travel | 315 mm |
| Rear Suspension | Pro-Link Showa single shock with spring preload, 13-position low-speed compression, high-speed compression and 17-position rebound adjustment |
| Rear Suspension Travel | 315 mm |
| Fork Oil | Pro Honda HP Fork Oil 5W or equivalent; standard outer-tube capacity 371 ml per leg with standard spring; fork damper fill 178 ml |
Brakes & Wheels
| Front Brake | Single 240 mm hydraulic disc, twin-piston caliper |
| Rear Brake | Single 240 mm hydraulic disc |
| Front Wheel Size | 21 x 1.60 in |
| Rear Wheel Size | 19 x 1.85 in |
Service Data
| Fuel Type | Unleaded petrol, 91 pump octane (R+M)/2 or higher |
| Premix Information | Not applicable - four-stroke engine with separate engine lubrication |
| Gearbox Oil | Separate transmission oil system; Pro Honda HP Trans Oil, Pro Honda GN4 or HP4 10W-40 without molybdenum additives, or equivalent JASO MA oil; 600 ml at oil change |
| Air Filter | Washable two-stage oiled foam element |
| Service Notes | Competition four-stroke motocross machine with separate engine and transmission lubrication. Inspect engine oil, transmission oil, valve clearance, air filter, coolant, clutch, drive chain, brakes and suspension at competition-service intervals. |
2005 Honda CRF250R – Refining Honda’s First 250 Four-Stroke
The 2005 Honda CRF250R was an evolutionary update rather than a new generation. The aluminium-framed platform introduced in 2004 remained, but Honda made worthwhile changes to the engine, transmission, clutch, suspension and chassis to sharpen the young CRF250R package.
The 249 cc Unicam engine retained its 78.0 x 52.2 mm bore and stroke, while revised cylinder-head porting, a new camshaft profile and updated ignition mapping were aimed at producing stronger power at lower rpm. Honda also fitted a revised spark plug and improved transmission and clutch lubrication. The 37 mm Keihin FCR carburettor remained, and owners working on worn induction components can compare replacement carburettor options.
Chassis changes included a lighter, stronger swingarm, revised front axle positioning and new fork and shock valving. The 47 mm Showa twin-chamber fork retained 315 mm of travel, matched by 315 mm at the Pro-Link rear suspension. The MXOwners fork oil reference is useful when servicing the adjustable Showa front end.
The 2005 model also retained Honda’s separate engine and transmission oil systems, a distinctive feature of these early CRF competition engines. Regular oil changes, valve-clearance checks and air-filter servicing remain essential. For owners rebuilding or maintaining one today, the MXOwners Parts Finder can help identify suitable replacement components.
