Husqvarna 129C Workshop Manual page 59

8.1 Troubleshooting
The various faults that can affect a trimmer are divided into four groups. In each group the likely
symptoms are given on the left and possible causes are listed on the right. The most likely faults are given
first, and so on.
Starting
Difficult to Stop screw for the throttle not
start working
Fuel filter blocked
The fuel hose blocked
Air in fuel ducts
Incorrect/poor fuel
The needle valve faulty
Needle valve's lever arm
damaged
Needle valve's lever arm does
not work correctly
Control diaphragm is damaged
Faulty seal of control diaphragm
Needle valve jams
Needle valve worn
Foreign object in the needle
valve guide
Flooding, fuel Loose screw(s) on the pump
leakage cover
Needle valve's lever arm
damaged
Needle valve's lever arm too high
Needle valve's lever arm does
not work correctly
Needle valve's spring is
deformed
Control diaphragm is damaged
Faulty seal of control diaphragm
Needle valve worn
Foreign object in the needle
valve guide
Difficult to Fuel filter blocked
prime when The fuel hose blocked
starting Air in fuel ducts
Flow bellows damaged
The needle valve faulty
Needle valve's lever arm does
not work correctly
Control diaphragm is damaged
Faulty seal of control diaphragm
Needle valve jams
Low speed
Engine does Stop screw for the throttle not
not idle working
Fuel filter blocked
The fuel hose blocked
Air in fuel ducts
Carburettor is not fitted correctly
Needle valve's lever arm does
not work correctly
Idles too Faulty heat insulation seal
slowly Needle valve's lever arm
damaged
Needle valve's lever arm too high
Needle valve's lever arm does
not work correctly
Needle valve worn
Foreign object in the needle
valve guide
Idling does Stop screw for the throttle not
not stabilize working
Fuel filter blocked
The fuel hose blocked
Air in fuel ducts
Incorrect/poor fuel
The needle valve faulty
Carburettor is not fitted correctly
Needle valve's lever arm does
not work correctly
Needle valve's spring is not fitted
correctly
Control diaphragm is damaged
Needle valve worn
Foreign object in the needle
valve guide
Stops when Stop screw for the throttle not
idling working
Fuel filter blocked
The fuel hose blocked
Air in fuel ducts
The needle valve faulty
Faulty heat insulation seal
Needle valve's lever arm too high
Needle valve's lever arm does
not work correctly
Needle valve's spring is
deformed
Needle valve's spring is not fitted
correctly
Needle valve worn
Foreign object in the needle
valve guide
Troubleshooting
59
English -