KYMCO ZX/SCOUT 50 Service Manual page 24

2
. GENERAL INFORMATION
POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS)
Inspection/Adjustment
Check ignition timing.
Check carburetor air
screw adjustment.
Check carburetor gasket
for air leaks.
Remove spark plug and
install it into spark plug
cap to test spark by
connecting it to engine
ground.
Remove auto bystarter
connecting wire and
check if bypass fuel
line is clogged.
Connect auto bystarter
wire to battery. Wait for
5 minutes, then connect
a hose to fuel enriching
circuit and then blow
the hose with mouth.
Symptom
Correct timing
Correctly adjusted
Incorrectly adjusted
No air leak
Good spark
Not clogged
Clogged
Incorrect timing
Air leaks
Weak or inter-
mittent spark
Clogged
Not clogged
ZX / SCOUT
Probable Cause
Faulty CDI unit
Faulty A.C. generator
Mixture too rich (turn screw
out)
Mixture too lean (turn screw
in)
Carburetor not securely
tightened
Faulty intake manifold gasket
Deformed carburetor O-ring
Faulty or fouled spark plug
Faulty CDI unit
Faulty A.C. generator
Faulty ignition coil
Broken or shorted high
tension wire
Faulty ignition switch
Broken auto bystarter wire
Faulty auto bystarter
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