KYMCO Grand Dink 250 Service Manual page 21

1
. GENERAL INFORMATION
POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS)
Inspection/Adjustment
Check ignition timing
Check carburetor pilot
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
Check carburetor air
cut-off valve
1-19
Symptom
Correct timing
Correctly adjusted
No air leak
Good spark
Good
Incorrect timing
Incorrectly adjusted
Air leaks
Weak or inter-
mittent spark
Faulty
GRAND DINK 250
Probable Cause
ÅFaulty CDI unit
ÇFaulty A.C. generator
ÅMixture too rich (turn screw
out)
ÇMixture too lean (turn screw
in)
ÅDamaged insulator rubber
ÇCarburetor not securely
tightened
ÉFaulty intake manifold
gasket
ÑDeformed carburetor O-ring
ÅFaulty or fouled spark plug
ÇFaulty CDI unit
ÉFaulty A.C. generator
ÑFaulty ignition coil
ÖBroken or shorted high
tension wire
ÜFaulty ignition switch
ÅDamaged air cut-off valve
diaphragm
ÇDamaged air cut-off valve
spring