DAELIM NS125DLX, Service Manual, Page: 183 / 191

20-1
Engine Does Not Start or Is Hard to Start 20-1
Engine Output Insufficient 20-2
Poor Performance at Low Speed and Idling 20-3
Poor Performance at High Speed 20-3
Unsatisfactory Operation 20-4
Fuel Gauge 20-6
Starter Motor 20-7
Engine Does Not Start or Is Hard to Start
1. Open the drain screw, and check Fuel not supplied (1) Fuel tank empty
fuel flow to the carburetor. to the carburetor (2) Fuel tube up to the fuel tank
clogged, or the vacuum tube or fuel
tube up to the inlet pipe clogged
(3) Float valve clogged
(4) Fuel tank cap air hole clogged
(5) Fuel supply pipe frozen
(6) Fuel strainer clogged.
2. Check spark plugs weak or no spark (1) Faulty spark plug
(2) Contaminated spark plug
(3) Faulty CDI unit
(4) Faulty A.C. generator
(5) Disconnected or shorted high
tension cord
(6) Disconnected or shorted ignition coil
(7) Faulty main switch
3. Test cylinder pressure. Low cylinder pressure (1) Piston ring seized
(2) Cylinder and piston ring won
(3) Cylinder and cylinder head cracked
(4) Crank case air leaks
(5) Cylinder head gasket damaged
4. Start engine in the following procedure Engine start but (1) Manifold air leaks
stops immediately (2) Inadequate ignition timing
5. Remove spark plugs. Plugs wet (1) Carburetor flooded
(2) Faulty control box
(3) Throttle valve excessively opened
Cause of Trouble
Fuel is supplied.
Good spark
Pressure normal
Engine will not start.
Dry plugs
20. Troubleshooting
20
Troubleshooting