Honda CRF450X 2008 Service Manual

TROUBLESHOOTING
ENGINE DOES NOT START OR IS HARD TO START
22-2
1. Fuel Line Inspection
Check fuel flow to carburetor.
Does fuel reach th e ca rburet or?
NO -. Clogged fuel hose or fuel strainer
• Clogged fuel valve
• Clogged fuel
tank breather hose
YES - GO TO S TE P 2.
2. Spark Plug Inspect ion
Remove and inspect spark plug.
Is th tt s park plug wet?
YES _ . Flooded carburetor
• Thr ottle valve open
• Dirty air cleaner
• Improperly adjusted pilot screw
NO - GO TO STEP 3.
3. Spark Test
Perform spark teS1.
Is th ere weak or no spa rk ?
YES _ . Faulty spark plug
• Fouled spark plug
•
l oose or disconnected ignition system wi res
• Broken or shorted ignit ion coil wire
• Faulty ignition coil
• Faulty igniting pulse generator
• F au l ty exciter coil
• Faulty engine st op button
• Faulty ignition contro l module ( leM)
NO - GO TO ST EP 4.
4. Engine Starting Condition
Start engine by normal procedure.
Do es the engine start then stops?
YE S - . Imprope r choke operation
• Incorrectly adjusted carburetor
• l eaking carburetor insulator
• Improper ignition timing (Faulty leM or ignition pulse generator)
• Contaminated fuel
•
Imprope r hot start operation
NO - GO TO STEP 5.
5. Cvlinder Compression Inspection
Test cylinder compression.
Is the compression low ?
YES - . Valve clearance too small
•
Va lve stuck open
• Worn cylinder and piston rings
• Damaged cylinder head gasket
• Seized valve
• Improper valve timing
• '05 - '07: Faulty decompressor cam
• After '07: Faulty decompressor shaft
•

Honda CRF450X 2008 Specifications

General

Brand	Honda
Model	CRF450X 2008
Category	Motorcycle
Language	English