Analysis Of Insufficient Engine Power - ZONGSHEN ZS250GY-3 Service Manual

The pressure is too
low.
Check whether the valve
e l e m e n t o f w h e e l h a s
leakage and whether wheel
is broken off.
Star t engine and gently turn
throttle control grip inward.
Observe the rev change of engine.
The engine rev will
enhance when the
gun is bigger
① Check whether oil supplying is blocked
and oil pressure value is between 240-
250KPa.
② Check whether fuel filter ,air filter and
muffler are blocked.
58

1.2 Analysis of Insufficient Engine Power

Engine power is
insufficient.
Support motorcycle with main stand,make it off the
ground and rotate wheel with hands.
Wheel r ota tes
freely.
C h e c k t h e
pressure of tire.
The pressure is
normal.
Dismantle spark plug and put your finger on
the screw thread hole of spark plug,then press
down the starting button or rapidly step the
starting lever.
Finger can feel strong gas rush
outward.Meanwhile there is
sound of flop,flop.
T h e c o m p r e s s i n g
pressure is normal.
The engine rev won't
enhance when stepping
on the accelerator.
C h e c k w h e t h e r e n g i n e
ignition is timing.
Yes
[1]Check whether there is something wrong
with CDI.
[2]Check whether the flywheel of generator
and trigering coil are loose.
W h e e l r o t a t e s
hardly.
[1]Check whether brake is dead.
[2]Check whether the axle of wheel is damaged
or worn.
[3]Check whether the insulator between the
wheel hub exists or is short.
Finger cannot feel strong
gas rush outward and the
compressing pressure of
cylinder is not enough.
The compressing
pressure is not enough.
[1]Check whether the outer connection of engine has
leakage.
[2]Check whether the valve ia timing.
[3]Check whether the valve clearance is too small.
[4]Check whether the seal between valve and valve holder is
good.
[5]Check whether piston ring breaks off or is dead or whether
its elasticity is not enough.
[6]Check the abrasion of piston ring and cylinder.
No