User Adjustment - Stihl FS 240 Service Manual

Setting idle speed
: Position screwdriver (1)
5910 890 2307 in low speed
screw L and high speed screw H
– Set idle speed with a speed
tester. Set the specified speeds
within the tolerance range of
± 200 rpm
1. Using the
idle speed screw LA
set speed to 3300 rpm
2. Turn the
low speed screw L
left or right to set the highest.
speed
If this speed is more than
3700 rpm, stop the adjustment and
start again with step 1.
3. With the
idle speed screw LA
set the speed again to
3300 rpm
4. With the low speed screw L
set the speed to 2800 rpm
Fine adjustment of the cut-off speed
is not required.
104
1
The fine adjustment of the high
speed screw H (1) and low speed
screw L (2) is now complete.
The settings of the high speed
screw H and the low speed screw L
can no longer be changed by the
user.

11.6.2 User adjustment

The new carburetors provide an
optimum fuel-air mixture in all
environments and operating states,
thus all that is eventually necessary
or possible is correction of the idle
speed using the idle speed screw
LA.
To avoid problems, the following
steps must be performed for all
settings:
– Troubleshooting, b 3.6
– Check cutting attachment, adjust
1 2
if necessary
– Examine the spark arresting
screen (if installed); clean or
replace it if necessary, b 3.7 or
b 5.1
– Examine air filter, replace if
necessary
– a dirty air filter may not be
cleaned, b 11.1
Check running behavior:
The engine must accelerate well
when the throttle is opened and idle
smoothly.
Setting the idle speed
The basic and fine adjustment of the
adjusting screws must be set.
– Let the engine warm up
Engine stops when idling
– Turn the idle speed screw LA
clockwise until the cutting
attachment begins to turn, then
back off 1 turn
Cutting attachment rotates
during idling
– Turn the idle speed screw LA
counterclockwise until the cutting
attachment stops turning, then
back off 1 turn
FS 240 C, FS 260 C, FS 360 C, FS 410 C, FS 460 C-M