KYMCO MYROAD 700i Service Manual page 27

1
. GENERAL INFORMATION
ENGINE LACKS POWER
Inspection/Adjustment
Connect the diagnostic
tool, then check EMS and
correct problems.
Start engine and
accelerate lightly for
observation
Check ignition timing
Check valve clearance
Test cylinder compression
Check fuel injector for
clogging
Remove spark plug and
inspect
Remove oil dipstick and
check oil level and condition
Remove cylinder head
bolts and inspect
Check if engine overheats
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 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
MYROAD 700i
Probable Cause
Clogged air cleaner
Clogged exhaust muffler
Faulty spark plug
Faulty throttle
Faulty fuel pump
Faulty fuel injector
Improper valve timing
Low or no compression
ECU
Faulty
Faulty CPS
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
Fouled fuel injector
Fouled spark plug
Incorrect heat range plug
Oil level too high
Oil level too low
Oil not changed
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
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