Engine Stalls, Hard To Start, Rough Idling - DAELIM HISTORY 125 Service Manual

TROUBLESHOOTING

ENGINE STALLS, HARD TO START, ROUGH IDLING

Open the drain screw, and check fuel
flow to the carburetor.
Fuel is supplied
Check the spark plug.
Not contaminated or not discolored
Insert the plug into cap, and check
sparks.
Sparks normal
Measure the cylinder compression.
(Using a compression gauge.)
Compression normal
Check the ignition timing.
Correct
Check the carburetor pilot screw
Adjustment normal
Check the intake air leak in the
connection part of carburetor insulator.
Not leak
Check for continuity between auto
bystarter terminals.
Continuity
Remove the auto bystarter from the
carburetor, check the starter valve.
Starter valve operates normally.
20-2
Fuel not supplied to
the carburetor.
Contaminated or
discolored.
Weak or intermittent
sparks.
Low or no cylinder
compression.
Incorrect
Misadjustment
Leak
No continuity
Starter valve won't
operate.
CAUSE OF TROUBLE
·No fuel to fuel tank.
·Clogged fuel tube.
·Clogged float valve.
·Clogged fuel tank cap.
·Clogged fuel strainer.
·Disconnected or damaged fuel pump
negative pressure tube.
·Contaminated spark plug.
·Using spark plug with an incorrect
heat range.
·Faulty or contaminated spark plug.
·Faulty A.C generator.
·Faulty ignition coil.
·Disconnected or short high tension cord.
·Faulty ignition switch.
·Faulty pluse generator.
·Faulty CDI unit.
·Worn cylinder or piston ring.
·Leaking cylinder gasket.
·Faulty valve clearance adjustment.
·Faulty A.C generator.
·Faulty CDI unit.
·Lean fuel mixture.
·Rich fuel mixture.
·Faulty carburetor insulator tightening.
·Faulty carburetor insulator O-ring.
·Faulty insulator band tightening.
·Faulty insulator.
·Lean fuel mixture.
·Rich fuel mixture.
·Slow circuit clogged.