Husqvarna 455 Rancher II - Page 58

58 – English
Acceleration and retardation
Does not
accelerate
The engine
stops when
releasing the
throttle
The engine
stops when
releasing the
throttle
Too rich
acceleration
Blocked air lter
Tank venting clogged
Blocked fuel lter
Blocked fuel line
Loose or faulty fuel pipe
Blocked impulse channel
The cover on the carburetor
pump side is loose
Faulty pump diaphragm
Leaking inlet hose (rubber)
Loose clamping screws
carburetor
Control system set too low
Control system incorrectly
assembled
Control system is binding
Faulty diffuser jet
Blocked mufer
Faulty pump diaphragm
Control system set too high
Control system is binding
Faulty diffuser jet
Blocked air lter
Faulty pump diaphragm
Faulty diffuser jet
8.2 Troubleshooting techniques
In addition to faults given in the above schematic,
troubleshooting can be carried out on a specic
component or specic chain saw system. The dif-
ferent procedures are described in the respective
sections and are as follows:
• Resistance testing the stop plate
• Pressure testing the carburetor
• Pressure testing the decompression valve
• Pressure testing the cylinder
High speed
Does not run
at full throttle
Low on power
Too lean
Blocked air lter
Tank venting clogged
Blocked fuel lter
Blocked fuel line
Loose or faulty fuel pipe
Impulse channel leaking
Blocked impulse channel
The cover on the carburetor
pump side is loose
Faulty pump diaphragm
Leaking inlet hose (rubber)
Loose clamping screws carburetor
Control system set too low
Damaged control system
Control system incorrectly
assembled
Leaking control diaphragm/cover
plate
Control system binding Blocked
mufer
Tank venting clogged
Blocked fuel lter
Impulse channel leaking
Blocked impulse channel
The cover on the carburetor
pump side is loose
Faulty pump diaphragm
Blocked air lter
Control system is binding
Leaking control system (air or fuel)
Control system incorrectly as-
sembled
Loose diaphragm rivet
Hole in the membrane
Leaking control diaphragm/cover
plate
Tank venting clogged
Blocked fuel lter
Blocked fuel line
Loose or faulty fuel pipe
Impulse channel leaking
Blocked impulse channel
The cover on the carburetor
pump side is loose
Faulty pump diaphragm
Leaking inlet hose (rubber)
Loose clamping screws carburetor
Control system set too low
Leaking control system (air or fuel)
Control system incorrectly as-
sembled
Loose diaphragm rivet
Hole in the membrane
Leaking control diaphragm/cover
plate
Troubleshooting