Analysis Of Engine Start - ZONGSHEN ZS250GY-3(EFI) Maintenance Manual

poor spark or no spark between electrode
Unscrew the cap of piston and check whether
there is spark spurt with high-voltage coil.
There is strong
blue spark spurt
Check whether there is some-
thing wrong with spark plug
and spark plug cap.
C h e c k t h e
power supply
of ignition elec-
trical source
Generator ignition
system has no con-
necting point.
[1]Check whether igni-
tion coil has short circuit
or open circuit.
[2]Check whether trig-
gering coil has short cir-
cuit or open circuit.
58

1.3 Analysis of Engine Start

Engine cannot be started or is hard
to be started.
Remove piston and check whether there is carbon deposit
between the electrode of spark plug.
No
Check whether there is spark spurt
between the electrode of spark plug.
There is strong blue and blue purple spark spurt be-
tween electrode.
poor spark or no
spark
Check whether the
Check whether
inner circuit of ig-
the ignition coil
nition system has
has short circuit
short circuit or
or open circuit.
open circuit.
[1]Check whether the outer connection of engine has leakage.
[2]Check whether valve is timing.
[3]Check whether valve clearance is too small.
[4]Check whether the seal of valve and valve holder is good.
[5]Check whether piston ring breaks off or is dead or has insufficient
elasticity.
[6]Check the abrasion of piston ring and cylinder.
Check whether air filter is blocked.
Check ignition system.
Clean out car-
bon deposit.
Check whether the engine igni-
tion is timing.
No
[1]Check whether there is some-
thing wrong with CDI device.
[2]Check whether the flywheel
of generator and triggering coil
are loose.
Yes
Check the compressing
pressure of cylinder with
Barometer
Ch ec k w he th er
the re i s so me-
thing wrong with
The cylinder
CDI device.
pressure is
sufficient .
The cylinder
pressure is
insufficient.
Dismantle spark plug
and check it.
The electrode of spark
plug is wet.
Dip a little gas in cylinder and try to start.
The running time is too
short or engine has flame-
out after starting.
Check with fault di-
agnosis tester
Yes
Yes
Pull out fuel injector, start ,
c h e c k w h e t h e r f u e l
spurted is atomised.
Check whether
there is gas in fuel
tank.
Add gas.
Yes
① Check whether venthole of fuel
tank cap is blocked.
② Check whether fuel filter is
blocked.
③ Check whether fuel nozzle is
blocked.④Check whether fuel tube
is broken.
⑤ Check whether connector of fuel
nozzle and fuel pump assembly is loose.
The electrode of spark
plug is dry.
Engine can continue
working after
starting.
Check with fault diagnosis
tester
No
ON