KYMCO MXU 50 REVERSE Service Manual page 36

1.
GENERAL INFORMATION
ENGINE LACKS POWER
Inspection/Adjustment
Start engine and
accelerate lightly for
observation.
Check ignition timing
(using a timing light).
Test cylinder
compression (using a
compression gauge)
Check carburetor for
clogging
Remove spark plug and
inspect
Check if engine
overheats
Rapidly accelerate or
run at high speed
1-33
Symptom
Engine speed does
Engine speed
not increase
increases
sufficiently
Correct timing Incorrect timing
Normal
compression
Not Clogged
Plug not fouled or
Plug fouled or
discolored
discolored
Engine does not
Engine overheats
overheats
Engine does not
Engine knocks
knock
Probable Cause
Clogged air cleaner
Clogged fuel filter
Clogged exhaust muffler
Faulty auto bystarter
Faulty charcoal canister
Faulty CDI unit
Faulty A.C. generator
Worn cylinder and piston
rings
Abnormal
Blown cylinder head gasket
compression
Faulty reed valve
Clogged Clogged carburetor jets
Fouled spark plug
Incorrect heat range plug
Mixture too lean
Poor quality fuel
Excessive carbon build-up in
combustion chamber
Ignition timing too early
Excessive carbon build-up in
combustion chamber
Poor quality fuel
Clutch slipping
Mixture too lean
ATV 50