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:
Full-time professional
users:
every 3
months
Semi-professional
users (in agriculture
and construction):
every 6
months
Hobby and
occasional users:
every 12
months
38
Winter Operation
At temperatures below +50 °F
(+10 °C), preheat carburetor as
follows:
1
:
Use a suitable screwdriver to turn
the shutter (1) from the summer
position (s) to the winter position
(r) – the shutter must snap into
position.
If the carburetor box cover is
removed, the shutter can be turned
to the required position by hand.
Heated air is now drawn in from around
the cylinder and mixed with cold air –
this helps prevent carburetror icing.
:
At temperatures above +68 °F
(+20 °C): Turn the shutter back 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 -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.
When the cover plate is fitted, the
shutter must be in the winter position.
:
If your saw is very cold (frost or ice
on machine), start the engine and
keep it at a high idle speed (with
chain brake disengaged) until it
reaches normal operating
temperature.
In the event of engine running problems,
first check that conditions for use of the
cover plate still apply.
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".
MS 270, MS 270 C, MS 280, MS 280 C