Stihl MS 271 Manual page 92

: Insert screwdriver (1)
5910 890 2306 through the
opening (arrow) and into the low
speed screw L and high speed
screw H – push the screwdriver
through the pre-installed limiter
cap on the high speed screw H.
Adjust idle speed with a tachometer.
Adjust specified engine speeds
within a tolerance of ± 200 rpm.
1. Adjust engine speed with
idle speed screw (LA)
to 3,300 rpm.
2. Turn the low speed screw (L)
counterclockwise or clockwise
to obtain maximum engine
speed.
If this speed is higher than
3,700 rpm, abort the procedure and
start again with step 1.
3. Use the idle speed screw (LA)
to set the engine speed again to
3,300 rpm.
4. Use the low speed screw (L)
to set engine speed to
2,800 rpm.
MS 271 C, MS 291 C
5. Use the high speed screw (H)
1
to set the engine's maximum
speed to 13,000 rpm.
(starting with H = 1 1/2
turns open).
Do not attempt to make the mixture
any leaner after obtaining an engine
speed of 13,000 rpm – the ignition
module limits maximum engine
speed to 13,000 rpm. This speed
cannot be increased by making the
setting leaner. Making the mixture
over-lean increases the risk of
engine damage.
Checking position of limiter cap
Notch (arrow) in limiter cap (1) must
point vertically upwards.
: If necessary, use a screwdriver to
rotate the limiter cap (1)
counterclockwise as far as stop
– the notch (arrow) is at the top.
1
Securing the limiter cap
: Insert a drift through the
opening (arrow) and then push
home the limiter cap until it
engages.
This completes the basic setting of
the high speed screw H and the low
speed screw L .
The setting of the high speed
screw H is fixed when the limiter
cap (1) is recessed 2 mm in the
carburetor body.
1
91