Honda 2004 CRF250X Service Manual

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SERVICE INFORMATION
GENERAL
CYLINDER/PISTON
• This section covers maintenance of the cylinder and piston . These procedures can be done with the engine in stalled in
the frame.
• Befo re disassembly , clean the engine thoroughly to prevent dirt from entering it.
• Be careful not to damage the mating surfaces when removing the cy l inde r. Fo r example, do not use a screw d river to pry
the cylinder.
• Clean all disassembled parts with clean sol vent before inspection, use compressed air to dry the parts.
• Under racing condit ions , the piston and piston rings should be replaced after 15 hours of op eration. Replace the piston
pin after 15 hours of operation .
SPECIFICATIONS
Pi ston ,
piston
ring
clearance
to-ring
groove
clearance
i i
end gap
TOp
TROUBLESHOOTING
0.065 - O. lOa (0.0026 - 0.0039)
0.115 ( O.0045)
"
• Engine top-end problems usually affect engine performance. These pr oblems can be di agnosed by a compression test
or by tracing engine noise to the top-end with a sou nding rod stethoscope.
• If the performance is poo r at low speeds, check for white smoke in t he crankcase breather hose. If the hose is smoky,
check fo r a seized piston ring.
Compre ss ion too lo w, ha rd s tarting or poor perform ance at low speeds
• Leaking cylinder head gasket
• Worn, stuck or broken piston rings
• Worn or damaged cylinder and piston
• Loose spark plug
Compression too high , over -hea ting or knocking
• Excessive carbon build - up in cylinder head or on top of piston
Abnormal noi se
• Worn cylinder and piston
• Worn piston pin or piston pin hole
• Worn connecting rod small end
Excessive smoke
• Worn cylinder, piston and piston rings
• Improper installation of piston r ings
• Scored or scratched pi ston or cylinder wall
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Honda 2004 CRF250X Specifications

General

Brand	Honda
Model	2004 CRF250X
Category	Motorcycle
Language	English