KYMCO ZX Service Manual page 20

2
. GENERAL INFORMATION
ENGINE WILL NOT START OR IS HARD TO START
Inspection/Adjustment
Check if fuel reaches
carburetor by loosening
drain screw.
Remove spark plug and
install it into spark plug
cap to test spark by
connecting it to engine
ground.
Test cylinder
compression.
Start engine by
follow-ing normal
starting procedure.
Remove spark plug and
inspect again.
Wait for 30 minutes and
then remove the
carbu-retor auto choke
circuit hose and blow
the hose with mouth.
ENGINE STOPS IMMEDIATELY AFTER IT STARTS
Inspection/Adjustment
Symptom
Fuel reaches Fuel does not
carburetor
Weak or no spark
Spark jumps
Normal
compression
Engine does not
fire
Dry spark plug
Not clogged
Symptom
reach carburetor
Low or no
compression
Engine fires but
does not start
Wet spark plug
Clogged
ZX / SCOUT
Probable Cause
• Empty fuel tank
‚ Clogged float valve
ƒ Clogged fuel filter
„ Faulty auto fuel valve
• Faulty spark plug
‚ Fouled spark plug
ƒ Faulty CDI unit
„ Faulty A.C. generator
... Broken or shorted ignition coil
† Broken or shorted exciter coil
‡Faulty ignition switch
• Burned or worn cylinder
piston
‚ Faulty reed valve
ƒ Blown cylinder head gasket
„ Leaking crankcase
... Faulty crankcase oil seal
• Incorrectly adjusted idle speed
‚ Air leaking through intake
pipe
ƒ Incorrect ignition timing
• Flooded carburetor
‚ Throttle valve excessively
open
• Faulty auto bystarter
Probable Cause
2-16