2009 KTM 450SX-F
General Specifications
| Model | KTM 450 SX-F |
| Year | 2009 |
| Category | Motocross |
| Engine Type | Liquid-cooled single-cylinder four-stroke DOHC, 4 valves |
| Weight | Approximately 104.6 kg without fuel |
Engine
| Displacement | 449.3 cc |
| Bore x Stroke | 97.0 x 60.8 mm |
| Compression Ratio | 12.5:1 |
| Fuel System | Keihin FCR-MX 41 mm flat-slide carburettor with accelerator pump | Replacement Options |
| Ignition | Kokusan fully electronic digital ignition with electronic advance |
| Spark Plug | NGK CR9EKB |
| Spark Plug Gap | 0.70 mm |
| Cooling System | Liquid cooling with mechanically driven water pump; 1.2 L coolant capacity |
| Starting System | Electric starter |
Transmission
| Transmission | 4-speed constant-mesh manual |
| Clutch | Wet multi-disc clutch, hydraulically operated |
| Final Drive | Chain, 14:52 standard sprocket ratio |
Dimensions
| Overall Length | |
| Overall Width | |
| Overall Height | |
| Wheelbase | 1475 ± 10 mm |
| Ground Clearance | 380 mm unloaded |
| Seat Height | 985 mm unloaded |
| Fuel Capacity | Approximately 8.0 L |
Chassis
Suspension
| Front Suspension | WP Suspension 4860 MXMA CC 48 mm upside-down closed-cartridge fork | Fork Oil Levels |
| Front Suspension Travel | 300 mm |
| Rear Suspension | WP Suspension PDS 5018 DCC monoshock with linkless Progressive Damping System |
| Rear Suspension Travel | 335 mm |
| Fork Oil | SAE 5 fork oil |
Brakes & Wheels
| Front Brake | 260 mm hydraulic disc with floating caliper |
| Rear Brake | 220 mm hydraulic disc with floating caliper |
| Front Wheel Size | 21 in |
| Rear Wheel Size | 19 in |
Service Data
| Fuel Type | Premium unleaded petrol, minimum 95 RON |
| Premix Information | Not applicable - four-stroke engine |
| Gearbox Oil | Engine and gearbox share lubrication; approximately 1.35 L SAE 10W-50 four-stroke motorcycle oil suitable for wet clutches |
| Air Filter | Washable oiled foam element |
| Service Notes | Competition four-stroke requiring frequent engine-oil and filter changes, air-filter servicing and regular inspection of valve clearance, cam-chain condition, spark plug, clutch, chain, battery and suspension components. |
2009 KTM 450 SX-F: More Usable Power and Better Suspension
The 2009 KTM 450 SX-F was a substantial refinement of the existing generation rather than a completely new motorcycle. KTM retained the 449.3 cc DOHC engine, electric starter, four-speed gearbox and chrome-molybdenum chassis, but concentrated on the areas riders had criticised most strongly: suspension compliance and the delivery of the powerful engine.
Engine changes included a lighter piston, revised valve springs, lighter finger followers, altered cam timing and reshaped intake and exhaust ports. These changes helped the engine rev more freely while also improving bottom-end response. The Keihin FCR-MX 41 mm accelerator-pump carburettor remained, and owners maintaining one today can compare alternatives through the MXOwners carburettor reference.
The WP suspension received significant attention. The 48 mm closed-cartridge fork used revised valving, different bottoming control and lighter tubes with altered flex characteristics, while the PDS rear shock was also retuned. The result was a noticeably more compliant motorcycle than the firmer 2008 version. Owners rebuilding the original fork can use the MXOwners fork oil reference when checking service information.
The 2009 bike also gained revised Brembo brake and clutch controls, including a lighter front-brake system. Electric starting remained one of the KTM's defining advantages, while the unusual four-speed gearbox continued for one more season. Historically, the 2009 450 SX-F represents KTM refining its distinctive formula before the larger chassis and transmission changes that arrived for 2010.
