Basic Setting (Carburetor With Limiter Caps) - Stihl MS 650 Manual

Adjustments for operation at
high altitude
A minor correction may be
necessary if engine power is not
satisfactory when operating at high
altitude.
– Check standard setting.
– Warm up the engine.
– Turn high speed screw (H) very
slight clockwise (leaner) no
further than stop.
If the setting is made too lean there
is a risk of engine damage due to
insufficient lubrication and
overheating.
82
12.5 Basic Setting
(Carburetor with
Limiter Caps)
The limiter caps have to be
removed from the adjusting screws
only if it is necessary to replace the
high speed screw (H) or low speed
screw (L), clean the carburetor or
carry out the basic setting.
Perform the following
operations:
After removing the limiter cap it is
necessary to carry out the basic
setting.
: Screw puller 5910 890 4500
about 5 turns counterclockwise
into the limiter cap.
1 2
: Use the puller to turn the limiter
cap on the low speed screw L
clockwise as far as stop, then
turn it back one quarter turn so
that its slot (1) is in line with the
slot (2) in the carburetor body –
limiter cap's lug must be visible
through the slot in the carburetor
body.
: Marks on limiter cap and
segment are in alignment
(arrow).
Note:
The lug is in line with the slot.
On older machines, the limiter cap's
lug is at 90° to the slot. Align the lug
relative to the slot by eye.
: Pull off the limiter cap.
MS 650, MS 660
L