TPC90 Operations Manual

3.7.2 Engine Troubleshooting
SYMPTOM
Difficult to start, fuel is
available, but no
SPARK at spark plug.
Difficult to start, fuel is
available, and SPARK is
present at spark plug.
POSSIBLE CAUSES
Spark plug bridging.
Carbon deposit on spark plug.
Short circuit due to deficiency.
Improper spark plug gap.
ON/OFF switch is shorted.
Ignition coil defective.
Improper spark gap, points dirty.
Condenser insulation
worn or short circuiting.
Spark plug wire broken
or short circuiting.
SOLUTION
Check gap, insulation or
replace spark plug.
Clean or replace spark plug.
Check spark plug insulation,
replace if needed.
Set to proper gap.
Check switch wiring, replace switch.
Replace ignition coil.
Set correct spark gap and clean points.
Replace condenser.
Replace defective spark plug wiring.
Difficult to start, fuel is
available, SPARK is
present, and
compression is normal.
Difficult to start, fuel
is available, spark is
present, and
compression is low.
No fuel present
at carburetor.
“Weak in power”
compression is
proper but misfires.
Wrong fuel type.
Water or dust in fuel system?
Air cleaner dirty.
Suction/exhaust valve
stuck or protruded?
Piston ring and/or cylinder worn.
Cylinder head and/or spark
plug not tightened properly.
Head gasket and/or spark
plug gasket damaged.
Fuel not available in fuel tank.
Fuel cock does not open properly.
Fuel filter clogged.
Fuel tank cap breather
hole clogged.
Air in fuel line.
Water in fuel system.
Dirty spark plug.
Ignition coil defective.
Flush fuel system and replace
with correct type of fuel.
Flush fuel system.
Clean or replace air cleaner.
Re-seat valves.
Replace piston rings and or piston.
Torque cylinder head bolts and
spark plug.
Replace head and spark plug gaskets.
Fill with correct type of fuel.
Apply lubricant to loosen fuel
cock lever, replace if necessary.
Replace fuel filter.
Clean or replace fuel tank cap.
Bleed fuel line.
Clean or replace spark plug.
Flush fuel system and replace
with correct type of fuel.
Replace ignition coil.
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