KYMCO SUPER8 50 Service Manual page 23

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
1-22
Symptom
Engine speed does not
Engine speed
increase sufficiently
increases
Correct timing
Correct
Normal
compression
Not clogged
Plug not fouled or
discolored
Correct and not
contaminated
Valve train lubricated Valve train not
lubricated properly
properly
Engine does not
overheats
Engine does not knock
Clogged air cleaner
Poor quality fuel (Restricted)
Clogged fuel tank cap breather hole
Clogged exhaust muffler
Faulty auto bystarter
Split carburetor vacuum piston
diaphragm
Faulty auto fuel valve
Faulty CDI unit
Incorrect timing
Faulty pulser coil
Improper valve clearance
adjustment
Incorrect
Worn valve seat (valve stem too
protruding
Improper valve and seat contact
Abnormal
Worn cylinder and piston rings
compression Leaking cylinder head gasket
Improper valve timing
Clogged carburetor jets
Clogged
Fouled spark plug
Plug fouled or
discolored
Incorrect heat range plug
Oil level too high
Incorrect or
Oil level too low
contaminated
Oil not changed
Clogged oil pipe
Faulty oil pump
Worn cylinder and piston rings
Mixture too lean
Poor quality fuel
Engine overheats
Excessive carbon buildup in
combustion chamber
Ignition timing too early
Excessive carbon build-up in
combustion chamber
Poor quality fuel
Engine knocks
Clutch slipping
Mixture too lean
Ignition timing too early
SUPER8 50
Probable Cause