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