Honda NSS250S Manual page 709

TROUBLESHOOTING
ENGINE DOES NOT START OR IS HARD TO START
TROUBLESHOOTING
1. Spark Plug Inspection
Remove and inspect spark plug.
Is spark plug in good condition?
YES
NO
2. Spark Test
Perform spark test.
Is the spark good?
YES
NO
3. Starter Motor Inspection
Check the starter motor turns.
Does the starter motor turn?
YES
NO
4. PGM-FI System Inspection
Check the PGM-FI system (page 6-14).
Is the PGM-FI system normal?
YES
NO
5. Cylinder Compression Inspection
Test the cylinder compression.
Is the compression within specification?
YES
NO
6. Engine Start Condition
Start by following the normal procedure.
Does the engine start but then stops?
YES
26-2
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– GO TO STEP 2.
– • Incorrect spark plug heat range
• Incorrect spark plug gap
• Dirty air cleaner element
– GO TO STEP 3.
– • Faulty spark plug
• Fouled spark plug
• Broken or shorted spark plug wire
• Faulty ignition coil
• Faulty ignition switch
• Faulty engine stop switch
• Faulty engine stop relay
• Faulty CKP sensor
• Loose or disconnected ignition system wires
• Faulty PCM/ECM
– GO TO STEP 4.
– Faulty electric starter system (page 21-4)
– GO TO STEP 5.
– Faulty PGM-FI system (page 6-19)
– GO TO STEP 6.
– • Valve stuck open
• Valve clearance too small
• Worn cylinder and piston rings
• Damaged cylinder head gasket
• Seized valve
• Improper valve timing
– • Intake manifold leaking
• Improper ignition timing (faulty PCM/ECM or CKP sensor)
• Contaminated fuel
• Faulty IACV