Carburetor Adjustment - Stihl TS 400 Manual

STIHL TS 400
10.3

Carburetor adjustment

The ignition system of this cut-off
machine has been equipped with an
electronic maximum speed limiter.
Unlike the case in machines with
conventional ignition system, the
maximum speed cannot be set
beyond a predetermined limit by
adjusting the carburetor.
The machine similarly cannot be
trimmed to maximum performance by
adjusting the speed. Neither the
speed nor the power is increased by
setting an unduly lean carburetor
mixture; in fact, this merely increases
the risk of engine damage.
The carburetor is set to the standard
setting by the manufacturer before
delivery of the machine. This setting
represents the optimum setting for the
atmospheric and climatic conditions
prevailing at the manufacturing plant.
However, it may be necessary to
adjust the carburetor setting in order
to obtain optimum performance in
conditions differing from those at the
site of manufacture.
Standard setting
The standard setting must be set
first if the carburetor has to be
readjusted completely.
- Carefully turn both adjusting
screws clockwise as far as
possible.
They must then be adjusted as follows:
H = High-speed adjusting screw (1)
1 turn open
L = Low-speed adjusting screw (2)
1 turn open
Note: If a tachometer is not available,
the high-speed adjusting screw must
not be set to a leaner setting than
standard.
Minor adjustment may be necessary if
the machine is used at high altitudes
(mountains) or at sea level.
- Check air filter and clean it if
necessary
- Start engine and let machine
warm up
- Set correct idle speed (cutting
wheel must not rotate)
H = Turn high-speed adjusting
screw clockwise (leaner) at
high altitudes and counter-
clockwise (richer) at sea level.
The screws should only be
adjusted marginally and very
carefully - the slightest change
leads to a tangible change in
engine performance.
Adjust idle speed
Whenever the
L = low-speed adjusting screw
is adjusted, the
LA = idle-speed adjusting screw
(3) must usually also be
adjusted.
Engine stops when idling –
set standard setting!
LA = Turn idle-speed adjusting
screw clockwise until the
cutting wheel also begins to
turn - then turn it back
one-half turn.
Cutting wheel rotates at
idle speed -set standard
setting!
LA = Turn idle-speed adjusting
screw counterclockwise until
the cutting wheel stops -then
turn it on approx. another
one-half turn.
43