Troubleshooting; Engine Does Not Start Or Is Hard To Start - Honda 1998 VT750C Service Manual

21.
TROUBLESHOOTING
ENGINE DOES NOT START OR IS
HARD TO START 21-1
ENGINE LACKS POWER 21-2
POOR PERFORMANCE AT LOW
AND IDLE SPEED 21-3
POOR PERFORMANCE AT HIGH
SPEED
POOR HANDLING
21-4
21-4
ENGINE DOES NOT START OR IS HARD TO START
Possible cause
1. Check the fuel flow to carburetor - - - - - Not reaching - - - - - . . . . . Clogged fuel line and filter
I
c a r b u r e t o r ' .Pinched fuel valve vacuum tube
"70hlng oa,bu,eto, • Clogged fuel tank beeathe,
2. Perform a spark test - - - - - - - - - Weak or no spark
---.~.
Faulty spark plug
I .
Fouled spark plug
Good spark • Faulty ignition control module
• Broken or shorted spark plug wire
Faulty ignition switch
• Faulty ignition pulse generator
• Faulty engine stop switch
• Loose or disconnected ignition sys-
tem wires
3. Remove and inspect spark plugs - - - - - Wet plug - - - - - - . . • Flooded carburetor
I .
SE valve ON position
Good • Throttle valve open
~
• Air cleaner dirty
4. Start by following normal procedure - - - Engine starts but
---~.
• Improper choke operation
I
s t o p s ' Carburetor incorrectly adjusted
Engine does not start • Intake pipe leaking
j
.
Improper ignition timing (Faulty
ignition coil or ignition pulse gener-
ator)
• Fuel contaminated
5. Test cylinder compression - - - - - - - Low compression
---.~.
Valve clearance too small
• Valve stuck open
• Worn cylinder and piston ring
• Damaged cylinder head gasket
• Seized valve
• Improper valve timing
fD
21-1