Analysis Of Engine Start - ZONGSHEN ZS250GY-3 Service Manual

Remove spark plug piston and check whether there is carbon
deposit between the electrode of spark plug.
Check whether there is spark spurt
between the electrode of spark plug.
poor spark or no spark
between electrode
Unscrew the cap of spark plug and check whether
there is spark spurt with high-voltage coil.
T h e r e i s s t r o n g
poor spark or
blue spark spurt
no spark
Check whether there is
something wrong with spark
plug and spark plug cap.
Check whether
C h e c k t h e
t h e i g n i t i o n
power supply
coil has short
o f i gnitio n
circuit or open
e l e c t r i c a l
circuit.
source
Generator ignition
s y s t e m h a s n o
connecting point.
[1]Check whether the outer connection of engine
[1]Check whether
has leakage.
ignition coil has
[2]Check whether valve is timing.
short circuit or open
circuit. [3]Check whether valve clearance is too small.
[2]Check whether
[4]Check whether the seal of valve and valve
triggering coil has
holder is good.
short circuit or open
[5]Check whether piston ring breaks off or is dead
circuit.
or has insufficient elasticity.
[6]Check the abrasion of piston ring and cylinder.

1.3 Analysis of Engine Start

Engine cannot be started or is
hard to be started.
Check ignition system.
No
There is strong blue and blue purple spark
spurt between electrode.
Check whether engine ignition is
timing.
[1]Check whether the CDI
device has problems.
[2]Check whether the
flywheel of generator and
the triggering coil are
loose.
C h e c k
Check whether
whether there
the inner circuit
is something
of ignition system
wrong with CDI
has short circuit or
device.
open circuit.
The cylinder
p r e s s u r e i s
insufficient
T h e e l e c t r o d e o f
spark plug is wet.
Check whether air filter is
blocked.
C h e c k w i t h f a u l t
diagnosis tester
Yes
Clean out carbon deposit.
No
Pull out fuel injector,
start ,check whether
f u e l s p u r t e d i s
atomised.
Yes
Check the compressing
pressure of cylinder with
Barometer
The cylinder
pressure is
sufficient.
[1]Check whether the air hole of
.
fuel tank cap is blocked.
[2]Check whether air cleaner
and fuel switch are blocked.
[3]Check whether fuel switch is
in good working condition.
[4]Check whether fuel tube is
broken.
[5]
Check whether connector of fuel
nozzle and fuel pump assembly is
loose.
Dismantle spark
plug and check it.
The electrode of
spark plug is dry.
Dip a little gas in cylinder and
try to start.
The running time is
too shor t or engine
has flameout af ter
starting.
C h e c k w i t h f a u l t
diagnosis tester
Yes
No
Check whether
t h e r e i s g a s i n
fuel tank.
No
Add gas.
Yes
Engine can continue
working after starting.
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