5.5.1 Removing And Installing - Stihl MS 341 Shop Manual

5.5 Checking Operation of
Chain Brake
The chain brake is one of the most
important safety devices on the
chainsaw. Its efficiency is measured
in terms of the chain braking time,
i.e. the time that elapses between
activating the brake and the saw
chain coming to a complete
standstill. The shorter the braking
time, the better the efficiency and
protection offered against being
injured by the rotating chain.
Contamination (with chain oil, chips,
fine particles of abrasion, etc.) and
smoothing of the friction surfaces of
the brake band and clutch drum
impair the coefficient of friction.
This, in turn, reduces the frictional
forces and thus prolongs the
braking time. A fatigued or stretched
brake spring has the same negative
effect.
– Start the engine.
– With the chain brake activated
(locked), open the throttle wide
for a brief period (max. 3
seconds) – the chain must not
rotate.
– With the chain brake released,
open the throttle wide and
activate the brake manually – the
chain must come to an abrupt
stop.
The braking time is in order if
deceleration of the saw chain is
imperceptible to the eye.
If the chain brake does not operate
properly, see troubleshooting chart
– b 4.1.
MS 341, MS 361, MS 361 C
5.5.1 Removing and Installing
(without QuickStop
Super)
3
4
Removing
– Troubleshooting chart – b 4.1
– Remove the clutch drum –
b 5.1
: Take out the screw (1).
: Remove the side plate (2).
: Take out the screws (arrows).
: On machines with carburetor or
carburetor/handle heating,
remove the ground wire (4).
: Remove the cover (3).
– Engage the chain brake by
pushing the hand guard away
from the front handle.
1
2
: Carefully ease the brake spring
(1) off the anchor pin (2).
: Remove the brake spring (1) from
the brake lever (3).
2 1
: Take out the screw (arrow).
: Pry the brake band (1) out of the
crankcase (arrow).
: Disconnect the brake band from
the brake lever (2).
3
Install a new brake band if there are
noticeable signs of wear (large
areas on inside diameter and/or
parts of outside diameter) and its
remaining thickness is less than
0.6 mm.
2
1
21