Engine Lacks Power - KYMCO xciting 500 User Manual

1
. GENERAL INFORMATION

ENGINE LACKS POWER

Inspection/Adjustment
Start engine and
accelerate lightly for
observation
Check ignition timing
(using a timing light)
Check valve clearance
Test cylinder compression
Check carburetor for
clogging
Remove spark plug and
inspect
Remove oil dipstick and
check oil level and condition
Remove cylinder head oil
pipe bolt and inspect
Check if engine overheats
Rapidly accelerate or run
at high speed
Symptom
Engine speed
increases
Correct timing
Correct
Normal
compression
Not Clogged
Plug not fouled or
discolored
Correct and not
contaminated
Valve train lubricated
properly
Engine does not
overheats
Engine does not knock
Engine speed does
not increase
sufficiently
Incorrect timing
Incorrect
Abnormal
compression
Clogged
Plug fouled or
discolored
Incorrect or
contaminated
Valve train not
lubricated properly
Engine overheats
Engine knocks
XCITING 500/250
Probable Cause
Clogged air cleaner
Restricted fuel flow
Clogged fuel line between fuel
tank and carburetor
Clogged exhaust muffler
Faulty auto bystarter
Split carburetor vacuum piston
diaphragm
ignition
Faulty unit
Faulty A.C. generator
Improper valve clearance
adjustment
Worn valve seat (valve stem too
protruding
Improper valve and seat contact
Worn cylinder and piston rings
Blown cylinder head gasket
Flaws in cylinder head
Improper valve timing
Clogged carburetor jets
Fouled spark plug
Incorrect heat range plug
Oil level too high
Oil level too low
Oil not changed
Clogged oil pipe
Faulty oil pump
Insufficient coolant
Faulty thermostat
Worn cylinder and piston rings
Mixture too lean
Poor quality fuel
Excessive carbon buildup in
combustion chamber
Ignition timing too early
Air in cooling system
Excessive carbon build-up in
combustion chamber
Poor quality fuel
Clutch slipping
Mixture too lean
Ignition timing too early
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