Honda SH300I 2006, Manual

Page: 503 / 511

TROUBLESHOOTING
25-2
TROUBLESHOOTING
ENGINE DOES NOT START OR IS HARD TO START
1. Spark Plug Inspection
Remove and inspect spark plug.
Is spark plug in good condition?
YES – GO TO STEP 2.
NO – • Plug not serviced frequently enough
• Incorrect spark plug heat range
• Incorrect spark plug gap
• Dirty air cleaner element
2. Spark Test
Perform spark test.
Is there weak or no spark?
YES – • Faulty spark plug
• Fouled spark plug
• Opened or shorted spark plug wire
• Broken spark plug cap
• Broken or shorted ignition coil
• Faulty CKP sensor
• Loose or disconnected ignition system wires
• Faulty ECM
NO – GO TO STEP 3.
3. Fuel Pump Inspection
You should hear the pump hum when the ignition switch is turned "ON".
Is the hum heard?
YES – GO TO STEP 4.
NO – • Broken fuel pump wire
• Faulty fuel pump
4. Cylinder Compression Inspection
Test the cylinder compression.
Is the compression within specification?
YES – GO TO STEP 5.
NO – • Valve stuck open
• Worn cylinder and piston rings
• Damaged cylinder head gasket
• Seized valve
• Incorrect valve seat contact
• Improper valve timing
5. Fuel Flow Inspection
Inspect the fuel flow (page 6-48).
Is the fuel flow within specification?
YES – GO TO STEP 6.
NO – • Clogged fuel feed hose
• Faulty fuel pump
6. Engine Start Condition
Start the engine by following the normal procedure.
Does the engine start but then stops?
YES – • Inlet pipe leaking
• Improper ignition timing (faulty ECM or CKP sensor)
• Contaminated fuel
• Clogged IACV passage