Honda CRF450X 2010 User Manual

CYLINDER/PISTON
TROUBLESHOOTING
• Engine top-end problems usually affect engine performance. These problems can be diagnosed by a comp ression test
or by tracing engine noise to the top-end with a sounding rod stethoscope.
• If the performance is poor at low speeds, check for white smoke in the crankcase breather hose. If the hose is smoky,
check for a seized piston ring.
Compression too low, hard starting or poor performance at l ow speeds
• Leaking cylinder head gasket
• Worn, stuck or broken piston rings
• Worn or damaged cylinder and piston
• Loose spark plug
Co mpr ession too high, ove r .heat in g or knocking
• Excessive carbon build-up in cylinder head or on top of piston
Abnormal noise
• Worn cylinder and piston
• Worn piston pin or piston pin hole
•
Worn connecting rod small end
• Worn connecting rod big end
Excessive s mok e
• Worn cylinder, piston and piston rings
• Improper installation of piston rings
• Scored or scratched piston or cylinder wall
10-4

Honda CRF450X 2010 Specifications

General

Engine Type	449cc liquid-cooled single-cylinder four-stroke
Bore and Stroke	96mm x 62.1mm
Compression Ratio	12.0:1
Transmission	Wide-ratio five-speed
Final Drive	#520 chain; 13T/51T
Front Suspension	47mm inverted Showa cartridge fork with 16-position rebound and 16-position compression damping adjustability; 12.4 inches travel
Front Brake	Single 240mm disc with twin-piston caliper
Rear Brake	Single 240mm disc
Front Tire	80/100-21
Rear Tire	110/100-18
Wheelbase	58.3 inches
Fuel Capacity	1.9 gallons
Ignition	Solid-state CD with electronic advance
Rear Suspension	Pro-Link Showa single shock with spring preload, 17-position rebound damping adjustability, and 13-position compression damping adjustability; 12.4 inches travel
Rake	27.38 degrees