Troubleshooting - Husqvarna HH 389MPC Operator's Manual

3. Remove the screw (C) from the spark arrestor (D) and
remove the spark arrestor from the muffler.
4. Clean the spark arrestor screen carefully with a wire
brush.
5. Examine the spark arrestor screen for wear and
damage. Replace the spark arrestor screen if it is
necessary.
CAUTION: Do not use a product with a
damaged spark arrestor screen.
6. Install the spark arrestor screen in the opposite
sequence.
Carburetor adjustment for high altitude operation
The altitude has an effect on the engine performance and
emissions. If the engine is always operated at altitudes
higher than 1500 m/5000 ft, it is necessary to adjust the
carburetor. Let your servicing dealer do the necessary
adjustments.
The engine does not start
Cause
The fuel valve lever is set to the OFF position.
The choke is open.
The ON/OFF switch is set to the OFF position.
There is no fuel in the fuel tank.
There is unsatisfactory fuel in the fuel tank.
No fuel stabilizer has been added or the fuel tank has not
been drained before storage.
The spark plug is damaged.
The spark plug is wet from fuel.
CAUTION: Speak to an approved servicing dealer
if the problem stays.
The power of the engine is decreased
Cause
The air filter is clogged.
1537 - 003 - 18.11.2022
CAUTION: Do not operate the engine on lower
altitudes if the carburetor is adjusted for high
altitudes. This causes engine damage. Let your
servicing dealer adjust the carburetor to factory
specifications.
Emission control system
This engine uses lean carburetor adjustments and other
systems to decrease the emissions of dangerous materials
in the exhaust fumes. The air intake, the fuel system
and the exhaust system are parts of the emission control
system. If modifications are done to the emission control
system, the emissions increase.
If modifications are done to the speed adjustment
mechanism or governor linkage, the engine does not
operate as intended. This can also cause increased
emissions.
It is necessary to use original spare parts to make sure
that the emission control system operates correctly.
The engine must be examined and repaired by an
approved servicing dealer if 1 or more of these problems
occur:
• The engine is not easy to start or stops again after a
start.
• The engine does not operate smoothly at idle speed.
• There are misfires in the engine during operation.
• The exhaust smoke is black or the fuel consumption is
high.

Troubleshooting

Solution
Move the fuel valve lever to the ON position.
Close the choke.
Set the ON/OFF switch to the ON position.
Fill fuel.
Drain the fuel tank and the carburetor. Refer to
fuel tank and carburetor on page 14 . Fill with clean fuel.
Do a check of the electrode gap or replace the spark plug.
Remove the spark plug and let it dry. Install the spark plug.
Solution
Clean or replace the air filter.
To drain the
13