KEEWAY F-ACT EVO Instruction & Maintenance Manual page 21

Underpowered engine failure diagnosis procedure
Air pressure too low
Check if the tire valve core
leaks and if the tire breaks
Fingers can feel a strong gas blowing
outside, with the sound of pow at the
same time
Cylinder compression pressure normal
Start the engine and step on the gas
slowly to watch the change of
engine's rotating speed
The rotating speed of the engine accelerates
as the driver step on the gas
1. Check if the clutch skids
2. Check if the transmission belt is over worn
3. Check if the centrifugal roller of the
driving pulley is over worn
4. Check if the conical surfaces of driving
wheel and moving friction wheel are over
worn or worn into groove
5. Check if the conical surfaces of following
pulley and moving following pulley are
over worn or worn into groove
6. Check if the roller track on the internal
side of moving friction wheel are over worn
or extruded into a drop pit
Prop up the main jiffy stand to make the wheels lift-off, revolve wheel by hand
Wheel spins smoothly
Check the tyre pressure
Remove the spark plug and block the spark
plug threaded hole with hand, then press the
starting button or step on the starting bar
quickly
The rotating speed of the engine does
Engine underpowered
Air pressure normal
not accelerate as the driver step on the
gas
Use ignition timing light to test
whether engine ignition is timing
Yes
1. Check if the supply of fuel feeding
system is smooth
2. Check if the carburetor, air cleaner and
exhaust muffler block
3. Check if the vacuum diaphragm of
carburetor plunger valve cracks or
breaks
4. Check if carburetor float height is
improper
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Wheel spins stiffly
1. Check if the brake drags
2. Check if the wheel bearing is
overused or damaged
3. Check if the loading of hub's
central spacer is neglected or
shorter
Fingers can not feel a strong gas blowing outside
Cylinder compression pressure insufficient
1. Check if there is gas
leaking in
connections of the engine
2. Check if the piston ring
sticks in ring groove or
insufficient elasticity
3. Check the wearability of
piston ring and cylinder
No
1. Check if the CDI
ignition apparatus fails
2.
Check
magneto flywheel and
trigger winding loosen
external
if the