12
MAINTENANCE
3.4.2 Engine Troubleshooting
SYMPTOM
POSSIBLE CAUSE
SOLUTION
Spark plug bridging?
Check gap, insulation or replace
spark plug.
Carbon deposit on spark
plug?
Clean or replace spark plug.
Short circuit due to deficient
spark plug insulation?
Check spark plug insulation, replace
if worn.
Difficult to start,
"fuel is
available, but no
SPARK at spark
plug".
Improper spark plug gap?
Set to proper gap.
ON/OFF switch is shorted?
Check switch wiring, replace switch.
Ignition coil defective?
Replace ignition coil.
Improper spark gap, points
dirty?
Set correct spark gap and clean points.
Condenser insulation worn or
short circuiting?
Replace condenser.
Difficult to start,
"fuel is
available, and
SPARK is
present at the
spark plug".
Spark plug wire broken or
short circuiting?
Replace defective spark plug wiring.
Wrong fuel type?
Flush fuel system, and replace
with correct type of fuel.
Water or dust in fuel system?
Flush fuel system.
Air cleaner dirty?
Clean or replace air cleaner.
Difficult to start,
"fuel is vailable,
spark is present
and ompression
is normal".
Choke Open?
Close Choke.
Suction/exhaust valve stuck or
protruded?
Re-seat valves.
Piston ring and/or cylinder
worn?
Replace piston rings and or piston.
Cylinder head and/or spark
plug not tightened properly?
Torque cylinder head bolts and
spark plug.
Difficult to start,
"fuel is
available, spark
is present and
compression is
low".
Head gasket and/or spark
plug gasket damaged?
Replace head and spark plug gaskets.
