Troubleshooting - Honda CRF450R 2006 Owner's Manual

The items that are serviceable using this Manual
are followed by the page number reference in
parenthesis. The items that require use of the
Honda Service Manual are followed by an
asterisk.
POOR PERFORMANCE AT LOW AND UNSTABLE
IDLE SPEED
CHECK
1. Check if air INCORRECT
cleaner is over-
oiled (P-43)
CORRECT
2. Check if the insulator
LEAKING
is leaking
NOT LEAKING
3. Check carburetor INCORRECT
pilot screw
adjustment (P-128)
CORRECT
4. Check carburetor CLOGGED
jets and accelerator
pump for clogs
NOT CLOGGED
5. Try spark test WAKE OR
INTERMITTENT
GOOD SPARK
SPARK
6. Check for LOW
low compression.
CORRECT
POOR PERFORMANCE AT HIGH SPEED
CHECK
1. Disconnect fuel
line at carburetor
and check for
clogging (P-34)
UNRESTRICTED
FUEL FLOW
POSSIBLE CAUSES
• Over-oiled air cleaner.
2. Remove air
cleaner (P-43)
AIR FILTER
NOT DIRTY
• Loose insulator clamp
• Damaged insulator
3. Install a larger
carburetor main
jet (p-126)
CORRECT
• Fuel-air mixture too
lean (Turn the pilot
screw out) (P-128)
4. Check carbureator
• Fuel-air mixture too rich
jets for clogging
(Turn the pilot screw in)
NOT CLOGGED
(P-128)
5. Check valve
• Contaminants in the
timing
fuel
• Not cleaned frequently
CORRECT
enough (P-123)
6. Try spark test
• Faulty, carbon or wet
GOOD SPARK
fouled spark pulg (P-130)
• Faulty ignition control
module*
• Faulty alternator*
• Faulty ignition coil*
• Broken or shorted
spark plug wire.
• Faulty ignition pulse
generator*.
• Loose or disconnected
ignition system wires
• Faulty engine stop button
7. Check for
• Ring worn
low compression.
• Cylinder worn or
damaged
CORRECT
• Piston worn or
damaged
• Head gasket not
sealing
• Valve stick open
POSSIBLE CAUSES
FUEL FLOW • Lack of fuel in tank
RESTRICTED (P-34)
• Clogged fuel line
(P-34)
• Clogged fuel fill
cap breather tube
(P-34)
• Clogged fuel valve
(P-34)
• Clogged fuel filter
(P-35)
• Not cleaned
DIRTY
frequently enough
(P-43)
CONDITION
• Jet size wrong, rejet
WORSE
in the opposite
direction (P-128)
CLOGGED
• Contaminants in
the fuel
INCORRECT • Cam sprocket not
installed properly
WEAK OR
• Faulty, carbon or wet
INTERMITTENT fouled spark pulg
(P-130)
SPARK
• Faulty ignition control
module*
• Faulty alternator*
• Faulty ignition coil*
• Broken or shorted
spark plug wire.
• Faulty ignition pulse
generator*.
• Loose or disconnected
ignition system wires
• Faulty engine stop button
LOW • Ring worn
• Cylinder worn or
damaged
• Piston worn or damaged
• Head gasket not sealing
• Improper valve timing
• Valve stick open

Troubleshooting

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