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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

Winter Operation

At temperatures below +50 °F (+10 °C), preheat carburetor as follows:

 

KN

1

146BA000

 

: 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”.

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MS 270, MS 270 C, MS 280, MS 280 C