Category:
High-Performance Motocross
Target User:
Motocross racers, mechanics, and serious enthusiasts.
Segment:
450cc Motocross Competition
Features:
Factory-backed repair information, detailed procedures, and critical technical data.
Engine:
Complete disassembly, assembly, inspection, and tuning of the 450cc four-stroke engine.
Transmission:
Gearbox overhaul, clutch service, shifting mechanism maintenance.
Fuel System:
Carburetor (Keihin FCR MX) tuning, cleaning, jetting, and float bowl adjustment.
Ignition System:
Spark plug specifications, ignition timing checks, coil testing.
Cooling System:
Radiator maintenance, coolant specifications, water pump service.
Suspension Front:
WP USD (Upside-Down) forks: disassembly, seal replacement, oil level and viscosity, damping adjustments.
Suspension Rear:
WP Monoshock: linkage maintenance, shock absorber service, spring preload, damping adjustments.
Brakes Front:
Brembo hydraulic disc brake system: caliper service, pad replacement, fluid flush, rotor inspection.
Brakes Rear:
Brembo hydraulic disc brake system: caliper service, pad replacement, fluid flush, rotor inspection.
Wheels Tires:
Spoke tensioning, rim inspection, tire pressure recommendations, wheel bearing maintenance.
Electrical System:
Wiring diagrams, battery maintenance, lighting checks, starter motor inspection.
Frame Chassis:
Frame inspection, steering head bearing service, subframe checks.
Bodywork:
Fairing and plastics removal/installation, seat maintenance.
Maintenance:
Routine checks, lubrication, filter cleaning/replacement, valve clearance adjustment.
Troubleshooting:
Diagnostic flowcharts for common starting issues, performance problems, and operational faults.
Repair:
Step-by-step instructions for major component overhauls and part replacements.
Rebuild:
Complete engine teardown and reassembly guides.
Depth:
Comprehensive, covering from basic maintenance to complete engine rebuilds and diagnostics.
Detail Level:
Includes detailed part diagrams, exploded views, and photographic illustrations.
Engine Type:
Single-cylinder, 4-stroke, SOHC, 4 valves
Bore X Stroke:
97 mm x 60.8 mm
Compression Ratio:
12.6:1
Claimed Horsepower:
Approx. 50-54 HP (Varies by tuning and dyno)
Claimed Torque:
Approx. 40-43 Nm (Varies by tuning and dyno)
Carburetor:
Keihin FCR MX 41 (Flat slide, with hot start)
Fuel Type:
Unleaded premium gasoline (min. 95 RON)
Oil Type:
KTM recommends Motorex Power Synt 4T SAE 10W-50 or equivalent ester-based motorcycle oil.
Cooling Type:
Liquid-cooled, with integrated radiator fan.
Transmission Type:
5-speed, claw-shifted
Clutch:
Multi-disc wet clutch (DS – Double Slipper) operated hydraulically by Magura.
Gear Ratios:
1st: 31/13 (2.38), 2nd: 29/16 (1.81), 3rd: 27/19 (1.42), 4th: 24/21 (1.14), 5th: 22/23 (0.96)
Final Drive:
Chain drive (520 O-ring chain), typically 13T front sprocket / 50T rear sprocket (stock).
Wheelbase:
Approx. 1475 mm (58.07 in)
Seat Height:
Approx. 990 mm (38.98 in)
Ground Clearance:
Approx. 355 mm (13.98 in)
Dry Weight:
Approx. 106.5 kg (234.8 lbs)
Fuel Tank Capacity:
Approx. 7.5 liters (1.98 US gal)
Safety Class:
Competition Off-Road Motorcycle (Not Street Legal)
Braking System:
Powerful Brembo hydraulic disc brakes front and rear for superior stopping power.
Suspension Performance:
Advanced WP suspension designed for optimal control and impact absorption in extreme conditions.
Ergonomics:
Ergonomically designed cockpit and seating position for rider control and confidence.
Oil Change Interval:
Every 15 hours of riding, or as specified in the manual for optimal performance.
Air Filter Cleaning:
Frequent cleaning (e.g., every 2-5 hours) depending on dust conditions.
Valve Clearance Check:
Every 20-30 hours of riding, or as indicated by performance changes.
Engine Oil:
Motorex Power Synt 4T SAE 10W-50 or equivalent.
Coolant:
KTM Coolant (pre-mixed) or equivalent ethylene glycol-based coolant with corrosion inhibitors.
Brake Fluid:
DOT 4 hydraulic brake fluid.
Clutch Fluid:
DOT 4 hydraulic fluid (for Magura hydraulic clutch).
Common Wear Items:
Clutch plates, piston rings, valve seats, fork seals, wheel bearings, chain and sprockets.
Potential Faults:
Some owners report valve seat wear over extended periods of hard use, requiring professional attention.
Heritage:
KTM is renowned for its 'Ready to Race' philosophy, with a strong heritage in off-road motorsports, particularly motocross and enduro.
Sx F Lineage:
The SX-F line represents KTM's premier motocross offerings, consistently updated with new technologies and performance enhancements.
Manufacturing:
Primarily manufactured in Austria.
Racing Success:
KTM 450 SX-F models have consistently achieved top rankings and victories in professional motocross championships worldwide.
Review Consensus:
Generally praised for its powerful engine, agile handling, and premium components.
Certifications:
Meets FIM and AMA homologation standards for professional racing where applicable.
