Troubleshooting - Honda CR250R Owner's Manual & Competition Handbook

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 IDLE SPEEDS
CHECK
1. Check ignition
INCORRECT
timing*
CORRECT
2. Check carburetor
INCORRECT
air screw
adjustment
(P. 106)
CORRECT
3. Check if air is LEAKING
leaking past
manifold
NOT LEAKING
4. Try spark test
WEAK OR
INTERMITTENT
SPARK
GOOD SPARK
5. Check the throttle
INCORRECT
position sensor*
CORRECT
6. Check the RC
INCORRECT
valve system
(P. 55)
CORRECT
POOR PERFORMANCE AT HIGH SPEED
CHECK
1. Check ignition
timing*
POSSIBLE CAUSES
• Improper ignition
2. Disconnect fuel
timing (Faulty engine
line at carburetor
control unit)*
and check for
• Faulty alternator*
clogging (P. 35)
• Fuel-air mixture too
lean (Turn the air
screw in) (P. 106)
• Fuel-air mixture too
3. Remove air
rich (Turn the air
cleaner (P. 40)
screw out) (P. 106)
• Deteriorated reed
valve gasket
• Loose insulator
4. Check carburetor
clamp
jets for clogging
• Faulty insulator
• Faulty, carbon or wet
fouled spark plug (P. 48)
5. Install a larger
• Faulty engine control
carburetor main
unit*
jet (P. 106)
• Faulty alternator*
• Faulty ignition coil*
• Broken or shorted
spark plug wire
6. Check the RC
• Faulty throttle
valve system
position sensor*
(P. 55)
• Faulty RC valve
cables
• Excessive carbon
build-up on the RC
valve
• Faulty RC valve
INCORRECT
CORRECT
FUEL FLOW
RESTRICTED
UNRESTRICTED
FUEL FLOW
DIRTY
AIR CLEANER
NOT DIRTY
CLOGGED
NOT CLOGGED
CONDITION
WORSE
CORRECT
INCORRECT
CORRECT

Troubleshooting

POSSIBLE CAUSES
• Faulty alternator*
• Faulty engine control
unit*
• Faulty ignition pulse
generator*
• Lack of fuel in tank (P. 35)
• Clogged fuel line (P. 35)
• Clogged fuel fill cap
breather tube (P. 35)
• Clogged fuel valve (P. 35)
• Clogged fuel filter (P. 35)
• Not cleaned
frequently enough
(P. 40)
• Contaminants in the
fuel
• Jet size wrong, rejet
in the opposite
direction (P. 106)
• Faulty RC valve
cables
• Faulty RC valve
119 119
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