TROUBLESHOOTING
English – 49
Will not run at
full throttle
Low power
Will not “four-
stroke”
Acceleration och retardation
Does not
accelerate
Engine stalls
when throttle re-
leased
Over rich
acceleration
Adjust L screw
Adjust H screw
Blocked air fi lter
Blocked fuel tank vent
Blocked fuel fi lter
Fuel line blocked
Loose or damaged fuel hose
Impulse channel blocked
Loose cover on carburettor pump side
Faulty pump diaphragm
Leaking air intake hose (rubber)
Loose carburettor mounting bolts
Needle valve set too low
Metering system incorrectly
assembled
Needle valve assembly sticking
Faulty diff user jets
Blocked silencer
Adjust L screw
Adjust H screw
Faulty pump diaphragm
Needle valve set too high
Needle valve assembly sticking
Faulty diff user jets
Adjust L screw
Adjust H screw
Blocked air fi lter
Faulty pump diaphragm
Faulty diff user jets
Troubleshooting methods
In addition to the faults described in the above
table, trouble shooting can be carried out on specifi c
components or sub-systems of the chainsaw. The
various procedures are described in the relevant
chapters, see the contents page, as follows:
•
Checking the operation of the chain brake
•
Measuring the resistance of the stop plate
•
Pressure testing the carburettor
•
Pressure testing the decompression valve
•
Pressure testing the cylinder
High rpm
Adjust H screw
Blocked air fi lter
Blocked fuel tank vent
Blocked fuel fi lter
Fuel line blocked
Loose or damaged fuel hose
Impulse channel leaking
Impulse channel blocked
Loose cover on carburettor pump side
Faulty pump diaphragm
Leaking air intake hose (rubber)
Loose carburettor mounting bolts
Needle valve set too low
Metering system damaged
Metering system incorrectly
assembled
Leaking control diaphragm/cover plate
Needle valve assembly sticking
Blocked silencer
Adjust H screw
Blocked fuel tank vent
Blocked fuel fi lter
Impulse channel leaking
Impulse channel blocked
Loose cover on carburettor pump side
Faulty pump diaphragm
Blocked air fi lter
Needle valve assembly sticking
Leak in metering system (air or fuel)
Metering system incorrectly
assembled
Loose diaphragm rivet
Hole in diaphragm
Leaking control diaphragm/cover plate
Blocked fuel tank vent
Blocked fuel fi lter
Fuel line blocked
Loose or damaged fuel hose
Impulse channel leaking
Impulse channel blocked
Loose cover on carburettor pump side
Faulty pump diaphragm
Leaking air intake hose (rubber)
Loose carburettor mounting bolts
Needle valve set too low
Leak in metering system (air or fuel)
Metering unit incorrectly assembled
Loose diaphragm rivet
Hole in diaphragm
Leaking control diaphragm/cover plate
