Sym Citycom.300i, Service Manual

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1. GENERAL INFORMATION
1-13
B. Engine run sluggish (Speed does not pick up, lack of power)
Check and adjustment Fault condition Probable causes
Try gradual acceleration
and check engine speed
Engine speed can not be
increased.
1. change the fuel injector
Engine speed can be
increased.
Air cleaner clogged
Poor fuel supply
Lines in fuel tank evaporation system clogged
Exhaust pipe clogged
Fuel injector clogged.
Check ignition timing
(Using ignition lamp)
Ignition timing correct Incorrect ignition timing
Malfunction of ECU
Malfunction of AC generator
Check cylinder compression
pressure (using compression
pressure gauge)
Compression pressure correct No compression pressure
Cylinder & piston ring worn out
Cylinder gasket leaked
Sand hole in compression parts
Valve deterioration
piston can not be moved.
Check fuel injector clogged
or not
No foul or discoloration Fouled and discoloration
Remove spark plug
foul and discoloration
No foul or discoloration
Remove dirt
Incorrect spark plug heat range
Piston and cylinder worn out
Lean mixture
Poor fuel quality
Too much carbon deposited in combustion
chamber
Ignition timing too advanced
Normal Engine overheat
Check if engine over heat
Continually drive in
acceleration or high speed
No knock Knock
Too much carbon deposited in combustion
Malfunction of fuel injector.
Poor fuel quality
Ignition timing too advanced
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