Husqvarna 966451906 Manuale Utente

58

 - English

Troubleshooting

Does not 

accelerate

The engine 

stops when 

releasing the 

throttle

Blocked air filter

Tank venting clogged

Blocked fuel filter

Blocked fuel line

Loose or faulty fuel pipe

Blocked impulse channel

The cover on the carburettor 

pump side is loose

Faulty pump diaphragm

Leaking inlet hose (rubber)

Loose carburettor mounting

Control system set too low

Control system incorrectly 

assembled

Control system sticking

Faulty diffuser jet

Blocked muffler

Faulty pump diaphragm

Control system set too high

Control system sticking

Faulty diffuser jet

Blocked air filter

Faulty pump diaphragm

Faulty diffuser jet

In addition to faults given in the above schematic, 

troubleshooting can be carried out on a specific 

component or specific chain saw system. The 

different procedures are described in respective 

sections and are as follows:

•  Function check of chain brake
•   Resistance testing the stop plate
•   Pressure testing the carburettor
•   Pressure testing the decompression valve
•   Pressure testing the cylinder

Will not run  

at full throttle

Low power

Will not “four 

stroke”

Blocked air filter

Tank venting clogged

Blocked fuel filter

Blocked fuel line

Loose or faulty fuel pipe

Impulse channel leaking

Blocked impulse channel

The cover on the carburettor 

pump side is loose

Faulty pump diaphragm

Leaking inlet hose (rubber)

Loose carburettor mounting

Control system set too low

Damaged control system

Control system incorrectly 

assembled

Leaking diaphragm/cover plate

Control system sticking

Blocked muffler

Tank venting clogged

Blocked fuel filter

Impulse channel leaking

Blocked impulse channel

The cover on the carburettor 

pump side is loose

Faulty pump diaphragm

Blocked air filter

Control system sticking

Leaking control system (air or 

fuel)

Control system incorrectly 

assembled

Loose diaphragm

Hole in diaphragm

Leaking diaphragm/cover plate

Tank venting clogged

Blocked fuel filter

Blocked fuel line

Loose or faulty fuel pipe

Impulse channel leaking

Blocked impulse channel

The cover on the carburettor 

pump side is loose

Faulty pump diaphragm

Leaking inlet hose (rubber)

Loose carburettor mounting

Control system set too low

Leaking control system  

(air or fuel)

Control system incorrectly 

assembled

Loose diaphragm

Hole in diaphragm

Leaking diaphragm/cover plate