Troubleshooting; Troubleshooting Schedule - Husqvarna HS 139A Workshop Manual

7.1 Troubleshooting schedule

Start Cause
The product does not Out of fuel.
start.
The engine oil level is low.
Ignition wire is disconnected from spark plug. Connect ignition wire to spark plug.
Incorrect electrode gap on the spark plug.
The spark plug is defective or of incorrect
type.
The oil filter is clogged.
The carburetor is defective.
Incorrect ignition coils.
Incorrect cylinder pressure.
Incorrect valve play.
The cylinder cover is on correctly attached.
Damaged combustion chamber.
Dirty air filter.
Expired fuel.
Damaged valve, gasket or valve retainer.
No spark at the electrode joint.
Starter rope is not Incorrect oil weight.
easy to pull.
Incorrect valve clearance.
Bent engine crankshaft.
Overheating Cause
The engine is too hot. Damaged cylinder gasket.
Damaged sealing gasket.
The engine oil level is low.
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7 Troubleshooting

Solution
Fill fuel tank.
Do a check of the engine oil. Add engine oil if
it is necessary.
Adjust the distance between the 2 electrodes.
Replace the spark plug.
Do a check of the oil tube and the oil filter.
Disassemble the carburetor and do a check.
Clean and adjust the carburetor if it is neces-
sary.
Do a check of the ignition coils.
Do a check of the cylinder pressure.
Adjust the valve play.
Tighten the screws on the cylinder cover.
Replace the combustion chamber.
Clean or replace the air filter. Refer to
Empty fuel tank and fill with fresh fuel.
Replace the valve, the gasket or the valve re-
tainer.
Replace the ignition coils.
Replace the engine switch.
Change oil to correct viscosity.
Adjust valves. Refer to the manual of the en-
gine manufacturer.
Replace the crankshaft.
Solution
Replace the cylinder gasket.
Replace the sealing gasket.
Do a check of the engine oil. Add engine oil if
it is necessary.
.
Troubleshooting- 39