Stihl TS 440 - Adjusting the Carburetor

TS 440
English
43
Basic information
The ignition system of this cut-off
machine is equipped with an electronic
speed limiter. The maximum speed
cannot be increased beyond a specified
limit.
The carburetor comes with a factory-set,
standard setting.
The carburetor has been adjusted for
optimum performance and fuel
efficiency in a wide variety of operating
conditions.
Preparing the machine
N Turn off the engine
N Check the air filter – clean or replace
it if necessary
N Check the spark arresting screen in
the muffler – clean it if dirty or
replace it if damaged. Never
operate the machine without a
properly maintained and
undamaged spark arresting screen
in place
Restoring the standard carburetor
setting
N Turn the high speed adjusting
screw (H) counterclockwise as far
as possible (max. 3/4 turn)
N Turn the low speed adjusting
screw (L) clockwise as far as
possible – then turn it 3/4 turn
counterclockwise
Setting the idle speed
N Adjust to the standard setting
N Start the engine and let it warm up
If the engine stops when idling
N Turn the idle speed adjusting
screw (LA) clockwise until the
abrasive cutting wheel begins to
rotate – then turn it back at least
1 turn or until the wheel stops
rotating
WARNING
If the engine will not idle properly, have
the machine checked by an authorized
STIHL servicing dealer.
If the abrasive cutting wheel rotates
when the machine is at idle and the
brake is released
N Turn the idle speed screw (LA)
counterclockwise until the abrasive
cutting wheel stops running – then
turn another full turn in the same
direction
WARNING
If the abrasive cutting wheel continues to
rotate when the machine is at idle, even
after adjustment, have the cut-off
machine checked by an authorized
STIHL servicing dealer.
If the speed is erratic when idling or if the
machine exhibits poor acceleration
(despite adjustment to LA setting)
The idle setting is too lean.
N Turn the low speed adjusting
screw (L) approx. 1/4 turn
counterclockwise until the engine
runs and accelerates smoothly
If the idle speed cannot be increased
sufficiently via the idle speed adjusting
screw (LA) or if the engine stops when
changing from partial throttle to idle
speed
The idle setting is too rich.
Adjusting the Carburetor
370BA029 KN
370BA090 KN