2006 Honda CRF450R
General Specifications
| Model | Honda CRF450R |
| Year | 2006 |
| Category | Motocross |
| Engine Type | Liquid-cooled 4-stroke single-cylinder, Unicam OHC, 4 valves |
| Weight | 99.8 kg dry |
Engine
| Displacement | 449.4 cc |
| Bore x Stroke | 96.0 x 62.1 mm |
| Compression Ratio | 12.0:1 |
| Fuel System | Keihin FCR 40 mm flat-slide carburettor | Replacement Options |
| Ignition | Digital CDI / ICM electronic ignition with electronic advance |
| Spark Plug | NGK IFR8H11 or Denso VK24PRZ11; high-speed use: NGK IFR9H11 or Denso VK27PRZ11 |
| Spark Plug Gap | 1.0-1.1 mm |
| Cooling System | Liquid cooled |
| Starting System | Primary kick starter |
Transmission
| Transmission | 5-speed constant-mesh, 1-N-2-3-4-5 |
| Clutch | Wet multi-plate, coil spring |
| Final Drive | Chain, D.I.D. 520DMA2 |
Dimensions
| Overall Length | 2,191 mm |
| Overall Width | 825 mm |
| Overall Height | 1,262 mm |
| Wheelbase | 1,492 mm |
| Ground Clearance | 339 mm |
| Seat Height | 955 mm |
| Fuel Capacity | 7.2 L |
Chassis
Suspension
| Front Suspension | 47 mm Showa inverted telescopic cartridge fork with adjustable compression and rebound damping | Fork Oil Levels |
| Front Suspension Travel | 315 mm fork stroke; 280 mm wheel travel |
| Rear Suspension | Honda Pro-Link swingarm with Showa single shock, adjustable preload, compression and rebound damping |
| Rear Suspension Travel | 320 mm |
| Fork Oil | Pro Honda HP Fork Oil 5W or equivalent; standard outer chamber capacity 375 cc per leg; fork damper fill 190 cc |
Brakes & Wheels
| Front Brake | Hydraulic single disc |
| Rear Brake | Hydraulic single disc |
| Front Wheel Size | 21 in |
| Rear Wheel Size | 19 in |
Service Data
| Fuel Type | Unleaded petrol, 91 pump octane (R+M/2) or higher |
| Premix Information | Not applicable - 4-stroke engine with separate lubrication |
| Gearbox Oil | Pro Honda HP Trans Oil, or SAE 10W-40 JASO MA motorcycle oil without friction modifiers; 590 cc at oil change, 670 cc after disassembly |
| Air Filter | Washable oiled dual-stage foam air cleaner; use Pro Honda Foam Filter Oil or equivalent |
| Service Notes | Competition motorcycle with separate engine and transmission oil systems. Check and service frequently under race conditions. Standard cold valve clearance: intake 0.16 ± 0.03 mm, exhaust 0.28 ± 0.03 mm. |
2006 Honda CRF450R: Refining a Proven Motocross Weapon
The 2006 Honda CRF450R was not a completely new generation. The major redesign had arrived for 2005, when Honda introduced a substantially revised aluminium frame, bodywork and engine refinements. For 2006 Honda concentrated on improving the already successful package, making a series of relatively subtle changes aimed mainly at handling, mass centralisation and rider feel.
The most important change was the position of the engine. Honda revised the crankcases so the engine could sit with the crankshaft approximately 5 mm lower, while the radiators were also lowered. The exhaust system and other components were repositioned closer to the centre of the motorcycle. These changes reduced the perceived centre of gravity and were intended to make the CRF450R easier to turn without sacrificing its high-speed stability.
Honda also shortened the overall front fork length by around 7 mm while retaining the same fork stroke, and revised the suspension settings at both ends. The 47 mm Showa twin-chamber fork remains highly tunable today, although correct oil quantity and condition are important when rebuilding it. Owners servicing the suspension can use the MXOwners fork oil reference when checking oil information for older motocross machines.
The 449.4 cc Unicam engine remained fundamentally familiar, fed by a Keihin FCR carburettor and driving through a five-speed gearbox. Honda revised carburettor calibration for improved response rather than chasing a dramatic increase in peak power. For owners restoring or repairing an original machine, the MXOwners carburettor reference and MXOwners parts finder can help when identifying replacement components.
Today the 2006 CRF450R is remembered as part of one of Honda's strongest carburetted CRF450R generations. Its appeal is less about being a revolutionary model and more about Honda taking the successful 2005 platform and carefully sharpening the handling, lowering weight where possible and refining a package that was already highly competitive.
