Operation Manual

33MS 441
English / USA
Chain brake maintenance
The chain brake is subject to normal
wear. It is necessary to have it serviced
and maintained regularly by trained
personnel, such as your STIHL servicing
dealer, at the following intervals:
-
At temperatures below +50 °F
(+10 °C) preheat carburetor as
follows:
: Use the combination wrench or a
screwdriver to loosen the scew (1) –
open it at least one full turn.
: Turn the shutter (2) from the
summer position (s) to the winter
position (r) – it must engage
audibly.
: Tighten down the screw.
Machines with HD Filter:
: Install standard filter in place of the
HD filter.
The carburetor is now heated via the
preheating plate – this helps avoid icing
up.
At temperatures above +68°F (+20°C):
Always return the shutter to the summer
position (s).
This is essential to avoid engine
running problems and overheating.
At temperatures below +14 °F
(-10 °C)
It is advisable to fit the cover plate
(special accessory) on the fan cover in
extremely cold conditions (temperatures
below +14°F (-10°C), in powder or
drifting snow).
The cover plate partially blanks off the
slots in the fan cover to help prevent
snow being sucked into the machine.
If engine idle speed is erratic or
acceleration is poor
: Turn low speed screw (L) 1/4 turn
counterclockwise.
It is usually necessary to change the
setting of the idle speed screw (LA)
after making adjustments to the the low
speed screw (L) – see “Adjusting the
Carburetor”.
Full-time professional
users: every 3
months
Semi-professional
users (in agriculture
and construction): every 6
months
Hobby and
occasional users: every 12
months
Winter Operation