DAELIM NS125DLX Service Manual page 184

Troubleshooting
Engine output Insufficient
1. Gently accelerate engine.
Engine speed increases.
2. Check ignition timing.
Normal
3. Press the kick starter pedal to
check the cylinder pressure.
Normal
4. Check the carburetor for clogging
Not clogged.
5. Remove spark plugs
Not contaminated or discolored.
6. Check for engine overheating
Not overheated.
7. Accelerate suddenly or run at
Engine does not knock.
20-2
Engine speed does not
increase sufficiently
Abnormal
Low
Clogged
Contaminated or
discolored
Overheated
Engine knocks
Cause of Trouble
(1) Air cleaner clogged
(2) Insufficient fuel supply
(3) Fuel tank cap air hole clogged
(4) Muffler clogged
(1) Faulty CDI unit
(2) Faulty A.C. generator
(1) Cylinder and piston ring worn
(2) Cylinder head gasket damaged
(3) Cylinder and cylinder head cracked
(1) Unsatisfactory Carburetor maintenance
(1) Unsatisfactory plug maintenance
(2) Plugs with incorrect heat value used
(1) Cylinder or piston worn
(2) Lean fuel mixture
(3) Poor quality fuel used
(4) Carbon deposit inside the
combustion chamber excessive
(5) Ignition timing incorrect.
(1) Carbon deposit inside the
combustion chamber excessive
(2) Poor quality fuel used
(3) Lean fuel mixture