Taking Care Of The Guide Bar; Shroud; Air Filter System - Stihl MS 171 Instruction Manual

20 Taking Care of the Guide Bar

NOTICE
The chain contracts as it cools down. If it is not
slackened off, it can damage the crankshaft and
bearings.
19.2.4 After a long period of full-throttle oper‐
ation
After a long period of full-throttle operation, allow
engine to run for a while at idle speed so that the
heat in the engine can be dissipated by flow of
cooling air. This protects engine-mounted com‐
ponents (ignition, carburetor) from thermal over‐
load.
19.3 After finishing work
► Slacken off the chain if you have retensioned it
at operating temperature during work.
NOTICE
Always slacken off the chain again after finishing
work. The chain contracts as it cools down. If it is
not slackened off, it can damage the crankshaft
and bearings.
19.3.1 Short-term storage
Wait for engine to cool down. Keep the machine
with a full tank of fuel in a dry place, well away
from sources of ignition, until you need it again.
19.3.2 Long-term storage
See "Storing the machine"
20 Taking Care of the Guide
Bar
2
► Turn the guide bar over – every time you
sharpen the chain and every time you replace
the chain – this helps avoid one-sided wear,
especially at the nose and underside of the
bar.
► Regularly clean the oil inlet hole (1), the oil‐
way (2) and the bar groove (3)
0458-533-0121-E
► Measure the groove depth – with the scale on
the filing gauge (special accessory) – in the
area used most for cutting
Chain type
Picco
Rapid
Picco
Rapid
Rapid
If groove depth is less than specified:
► Replace the guide bar
The drive link tangs will otherwise scrape along
the bottom of the groove – the cutters and tie
straps will not ride on the bar rails.

21 Shroud

21.1
► Squeeze the throttle trigger and move the
Master Control lever to l .
► Slide the lock to the rear.
► Remove the shroud upwards to the rear.
21.2
► Refit the shroud and secure it with the lock.

22 Air Filter System

The air filter system can be adapted to suit differ‐
ent operating conditions by installing a choice of
filters. Changing the filter is quick and simple.
1
3
Chain pitch
1/4" P
1/4"
3/8" P
3/8"; 0.325"
0.404"
Removing the shroud
Installing the shroud
English
Minimum
groove
depth
4.0 mm
4.0 mm
5.0 mm
6.0 mm
7.0 mm
31