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ENGLISH
Section 1 Engine Fault Diagnostic Procedure
Chapter 4 Motorcycle Fault Diagnostic Procedure
1.1Fault diagnostic procedure for poor engine idling
Engine idles poorly
Check the combustible
mixture ratio
Adjust the
electrode
clearance
①
C h e c k i f t h e C D I
ignition is faulty
②
Check the magnetic
motor flywheel and trigger
coil for any looseness
Check if the spark
plug electrode
Check if the throttle control cable is
pulled flexibly in the cable sleeve
and if the throttle spring is too soft
Turn off the ignition switch,
stop for about 10 s, restart
after the idle stepper motor
returns
Use the diagnostic tool to check
Clean the idle bypass airway
Still no idle speed after cleaning
carbon deposition in bypass airway
Check the throttle body
idling bypass airway
①
Check the external joints
for any leakage
②
Check the air is distributed
at correct time
③
C h e c k i f t h e v a l v e
clearance is too small
④
Check the sealing between
valve and the valve seat
⑤
Check if the piston ring is
broken or stuck in the ring
groove or lack of elasticity
⑥
Check the piston ring and
cylinder for any abrasion
Normal compression
pressure in cylinder
Check if ignition timing
is proper or not
Pull the throttle and check
if it is completely closed
Check the cylinder
compression pressure
Engine idles unstably
Engine idles at too high speed
Engine does not idle
yes
No
I n s u f f i c i e n t
compression
p r e s s u r e i n
cylinder
If the idle speed is
still too high, use
the fault diagnostic
tool to check
Use the diagnostic tool
to check
yes
yes
No
No
