Market Position:
High-performance motocross competition bike
Key Competitors:
Yamaha YZ450F, Kawasaki KX450F, Suzuki RM-Z450
Engine Type:
Liquid-cooled, four-stroke, single-cylinder
Fuel Delivery:
Electronic Fuel Injection (PGM-FI)
Suspension Type:
Advanced Pro-Link rear and telescopic front suspension
Chassis Design:
Aluminum twin-spar frame for optimal rigidity and weight distribution
Engine System:
Complete engine tear down, inspection, and rebuild
Fuel System:
Fuel injection (PGM-FI), throttle body, fuel pump, injectors, fuel tank, lines
Ignition System:
CDI, ignition coil, spark plug, troubleshooting no spark
Transmission System:
Clutch, primary reduction gear, transmission gears, shift mechanism, lubrication
Suspension System Front:
Front forks (telescopic), oil seals, springs, damping adjustment, disassembly, and assembly
Suspension System Rear:
Pro-Link rear suspension, shock absorber, linkage, swingarm, bearings, lubrication
Brakes System Front:
Hydraulic disc brakes, caliper, master cylinder, brake pads, rotors, fluid type, bleeding
Brakes System Rear:
Hydraulic disc brakes, caliper, master cylinder, brake pads, rotors, fluid type, bleeding
Electrical System:
Battery, charging system (stator, rectifier), lighting (if applicable), wiring diagrams
Cooling System:
Radiator, hoses, coolant type and capacity, water pump
Exhaust System:
Muffler, exhaust pipes, gaskets, spark arrestor (if applicable)
Frame And Bodywork:
Frame inspection, plastic panels, seat, handlebars, footpegs, fenders
Maintenance Procedures:
Scheduled maintenance, oil changes, filter replacements, valve clearance adjustment, chain adjustment
Troubleshooting Guides:
Comprehensive troubleshooting for common issues, error codes, diagnostic procedures
Rebuild Procedures:
Complete engine overhaul, transmission rebuild, suspension rebuild
Repair Procedures:
Step-by-step repair instructions for all major components
Inspection Procedures:
Detailed inspection guidelines for critical engine and chassis components
Technical Depth:
Comprehensive, from basic maintenance to full engine and chassis overhaul
Diagnostic Capabilities:
Includes diagnostic information and troubleshooting for EFI system and general operation
Illustrations Diagrams:
Detailed pictures, part diagrams, and schematics for visual guidance
Searchability:
Yes, includes clickable chapters and is searchable
Printability:
Yes, no restrictions on printing
Engine Type:
Liquid-cooled, four-stroke, SOHC, single-cylinder
Bore X Stroke 2007:
96.0 mm x 62.1 mm
Bore X Stroke 2008:
96.0 mm x 62.1 mm
Compression Ratio:
12.0:1
Valve Train:
Unicam SOHC, 4 valves
Camshaft Timing:
Intake: 25° BTDC / 5° ABDC, Exhaust: 20° BBDC / 20° ATDC (example values, actual may vary)
Valve Clearance Intake:
0.16 mm (cold)
Valve Clearance Exhaust:
0.20 mm (cold)
Starting System:
Kickstarter
Horsepower Estimated:
Approx. 55-58 HP (at crankshaft, actual may vary)
Torque Estimated:
Approx. 36-39 lb-ft (at crankshaft, actual may vary)
Fuel Injection Type:
PGM-FI (Programmed Fuel Injection) with 40mm throttle body
Fuel Type:
Unleaded gasoline, 91 octane or higher recommended
Fuel Pump Pressure:
Refer to manual for exact specifications (typically in the range of 36-50 psi)
Idle Speed Rpm:
1,400 ± 150 rpm (engine warm)
Mixture Screw Setting:
Consult manual for specific baseline settings or diagnostic procedures
Transmission Type:
Constant-mesh, 5-speed sequential
Primary Reduction Gear Ratio:
3.043 (70/23)
Gear Ratios 1St:
2.615 (34/13)
Gear Ratios 2Nd:
1.941 (33/17)
Gear Ratios 3Rd:
1.556 (28/18)
Gear Ratios 4Th:
1.333 (28/21)
Gear Ratios 5Th:
1.143 (24/21)
Clutch Type:
Wet, multi-plate, cable-actuated
Transmission Oil Type:
SAE 10W-30 API SG or higher (Honda recommends their own GN4 or HP4)
Transmission Oil Capacity:
Approximately 0.80 Liters (0.85 US qt) after disassembly, consult manual for precise refill quantities.
Engine Oil Change:
Every 15 hours of use or annually, whichever comes first (refer to manual for race conditions)
Oil Filter Replacement:
Every oil change
Air Filter Cleaning:
After every 2-3 rides or as needed, especially in dusty conditions
Valve Clearance Check:
Every 100 hours of use or annually
Spark Plug Inspection:
Every 20 hours of use
Engine Oil Specification:
SAE 10W-30, API SG or higher (Honda GN4 or HP4 recommended)
Coolant Type:
Honda Motorcycle Coolant (or equivalent premium quality ethylene glycol based coolant with corrosion inhibitor) mixed 50/50 with distilled water
Brake Fluid Type:
DOT 4 (Honda recommends their own DOT 4 Brake Fluid)
Common Issues:
Refer to manual for troubleshooting specific issues like hard starting, poor idle, or power loss. Common wear items include clutch plates, wheel bearings, and linkage bearings.
Lubrication Points:
The manual details critical lubrication points for engine, transmission, suspension linkages, and bearings.
Brand Heritage:
Honda has a long and storied history in motorcycle racing, particularly in motocross and supercross, with a reputation for engineering excellence and reliability.
Crf Lineage:
The CRF450R is the flagship motocross model for Honda, representing years of development and innovation in four-stroke motocross technology. It succeeded the CR series.
2007 Updates:
The 2007 model saw significant updates including a new lighter aluminum frame, revised suspension settings, and an updated PGM-FI system for improved power delivery and handling.
2008 Updates:
The 2008 model built upon the 2007 revisions with further refinements to suspension valving, engine mapping, and chassis tuning for enhanced performance.
Production Location:
Japan (typical for Honda's high-performance models)
