Stihl 241 Cm Manual

							MS 241 C-M
English
39 If groove depth is less than specified:
NReplace 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.
Removing the shroud
NMove the Master Control lever to the 
stop position (0).
NPush the hand guard forward – the 
chain is locked.
NOpen the twist locks (1) by turning 
them 1/4 turn counterclockwise with 
the combination wrench. 
NRemove the shroud (2).
Installing the shroud
NPlace the shroud in position.
NClose the twist locks by turning 
them a 1/4 turn clockwise. If there is a noticeable loss of engine 
power
NRemove the shroud – see "Shroud"
Removing the air filter
NClean away loose dirt from around 
the filter
NOTICE
Do not use tools to remove and install 
the air filter – the air filter could be 
damaged in the process.
NTurn air filter 1/4 turn 
counterclockwise and remove in the 
direction of the rear handle
NAlways replace a damaged filter
Cleaning the air filter
NKnock out the filter or blow it clear 
with compressed air from the inside 
outwards
If knocking-out or blowing-out does not 
suffice, or in the case of stubborn dirt or 
stuck filter fabric, the filter must be 
subjected to a thorough cleaning. Chain 
typeChain pitch Minimum 
groove depth
Picco 1/4" P 0.16" (4.0 mm)
Rapid 1/4" 0.16" (4.0 mm)
Picco 3/8" P 0.20" (5.0 mm)
Rapid 3/8"; 0.325" 0.24" (6.0 mm)
Rapid 0.404" 0.28" (7.0 mm)
Shroud
1
1
1
5902BA027 KN
2
&OHDQLQJWKH$LU)LOWHU
1.
2.
2410BA016 KN 
						

							MS 241 C-M
English
40 Thorough filter cleaning
NWash the filter in STIHL special-
purpose cleaner (special 
accessory) or a clean, non-
flammable cleaning liquid (e. g., 
warm soapy water) – rinse the filter 
from inside to out under a water jet 
– do not use high-pressure cleaners
NDry all filter parts – do not expose to 
extreme heat
NDo not oil the filter
NReinstall filter
Installing the air filter
NFit air filter 
NPress the air filter in the direction of 
the filter housing and 
simultaneously turn it clockwise 
until the air filter engages – the 
"STIHL" logo must be horizontal
NFit the shroud – see "Shroud"Exhaust emissions are controlled by the 
design of the fundamental engine 
parameters and components (e.g. 
carburation, ignition, timing and valve or 
port timing) without the addition of any 
major hardware.
Basic information
M-Tronic regulates the fuel quantity and 
ignition timing for all operating states 
electronically.
M-
Tronic stands for easy, fast starting, 
constant optimum engine performance, 
outstanding acceleration and automatic 
adaptation to changes in operating 
conditions.
Manual carburetor adjustments are no 
longer required – the carburetor does 
not have any adjusting screws.
Automatic adjustment
Under extremely changed operating 
conditions, attainment of the optimal 
setting can be accelerated as follows:
NCarry out five uniform cuts to length 
under full load
2410BA017 KN
2.1.
(QJLQH0DQDJHPHQW07URQLF 
						

							MS 241 C-M
English
41 NIf engine performance deteriorates, 
check the spark arresting screen in 
the muffler
NLet the muffler cool down
NUnscrew the screw (1)
NPull out spark arresting screen (2)
NClean the dirty spark arresting 
screen, replace if damaged or 
heavily carbonized
NRefit the spark arresting screen
NFit screw
Removing the spark plug
NRemove the shroud – see "Shroud"
NPull off the spark plug boot
NUnscrew spark plug
Checking the Spark Plug
NClean dirty spark plug.
NCheck electrode gap (A) and 
readjust if necessary – see 
"Specifications."
NUse only resistor type spark plugs of 
the approved range.Rectify problems that have caused 
fouling of spark plug:
–too much oil in fuel mix,
–dirty air filter,
–unfavorable running conditions, e.g. 
operating at part load.
WARNING
T o  r e d u c e  t h e  r i s k  o f  f i r e  a n d  b u r n  i n j u r y ,  
use only spark plugs authorized by 
STIHL. Always press spark plug boot (1) 
snugly onto spark plug terminal (2) of the 
proper size. (Note: If terminal has 
detachable SAE adapter nut, it must be 
securely attached.) A loose connection 
between spark plug boot and ignition 
wire connector in the boot may create 
arcing that could ignite combustible 
fumes and cause a fire.
Spark Arresting Screen in 
Muffler
2310BA023 KN
2
1
6SDUN3OXJ
2410BA018 KN
000BA039 KNA
1
2
000BA071 KN 
						

							MS 241 C-M
English
42
Installing the spark plug
NFit spark plug by hand
NTighten the spark plug and press on 
the spark plug boot firmly
NFit the shroud – see "Shroud"
If engine is down on power, difficult to 
start or runs poorly at idling speed, first 
check the spark plug.
Fit a new spark plug after approx. 100 
operating hours or earlier if the 
electrodes are badly eroded.
Wrong fuel mix (too much engine oil in 
the gasoline), a dirty air filter and 
unfavorable running conditions (mostly 
at part throttle etc.) affect the condition 
of the spark plug. These factors cause 
deposits to form on the insulator nose 
which may result in trouble in operation.To help prolong the wear life of the 
starter rope, observe the following 
points:
NPull the starter rope only in the 
direction specified.
NDo not pull the rope over the edge of 
the guide bushing.
NDo not pull out the rope more than 
specified.
NDo not allow the starter grip to snap 
back, guide it back into the housing 
slowly – see chapter on "Starting / 
Stopping the Engine."
Have a damaged starter rope replaced 
by your dealer before it breaks 
completely. STIHL recommends that 
you have servicing and repair work 
carried out exclusively by an authorized 
STIHL servicing dealer.For periods of 3 months or longer
NDrain and clean the fuel tank in a 
well ventilated area.
NDispose of fuel properly in 
accordance with local 
environmental requirements.
NRun the engine until the carburetor 
is dry – this helps prevent the 
carburetor diaphragms sticking 
together.
NRemove the saw chain and guide 
bar, clean them and spray with 
corrosion inhibiting oil.
NThoroughly clean the machine – pay 
special attention to the cylinder fins 
and air filter.
NIf you use a biological chain and bar 
lubricant, e.g. STIHL BioPlus, 
completely fill the chain oil tank.
NStore the machine in a dry, high or 
locked location, out of the reach of 
children and other unauthorized 
persons.
2410BA019 KN
5HZLQG6WDUWHU6WRULQJWKH0DFKLQH 
						

							MS 241 C-M
English
43 NRemove chain sprocket cover, saw 
chain and guide bar.
NRelease chain brake – pull hand 
guard against the front handle
Fit new chain sprocket
–after use of two saw chains or 
earlier
–if the wear marks (arrows) are 
deeper than 0.02 in (0.5 mm) – 
otherwise the service life of the saw 
chain is reduced – use check gauge 
(special accessory) to test
Using two saw chains in alternation 
helps preserve the chain sprocket.
Use only STIHL original chain sprockets 
to help ensure reliable functioning of the 
chain brake.NUse a screwdriver to remove the E-
clip (1)
NRemove the washer (2)
NRemove rim sprocket (3) (if so 
equipped), clutch drum (4) and 
needle cage (6).
NInspect transport profile for rim 
sprocket on the clutch drum (4) – if 
there are also heavy signs of wear, 
also replace the clutch drum
NRemove clutch drum with integrated 
spur chain sprocket (5) (if so 
equipped) including needle cage (6) 
from the crankshaft – for 
powerheads with Quickstop Plus 
chain brake system, depress 
throttle trigger lockout beforehand
Install spur chain sprocket / rim sprocket
NClean crankshaft stub and needle 
cage and lubricate with STIHL 
lubricant (special accessory)
NSlide needle cage onto the 
crankshaft stub
NAfter refitting, turn the clutch drum 
and/or spur chain sprocket approx. 
1 full turn so that the carrier for the 
oil pump drive engages
NRefit the rim sprocket – cavities 
toward the outside
NRefit washer and E-clip on the 
crankshaftChecking and Replacing the 
Chain Sprocket
001BA121 KN
001BA122 KN
1 2
45
61
2 3 6 
						

							MS 241 C-M
English
44 Sawing effortlessly with a properly 
sharpened saw chain
A properly sharpened saw chain cuts 
through wood effortlessly even with very 
little pushing.
Never use a dull or damaged saw chain 
– this leads to increased physical strain, 
increased vibration load, unsatisfactory 
cutting results and increased wear.
NClean the saw chain
NCheck the saw chain for cracks and 
damaged rivets
NReplace damaged or worn chain 
components and adapt these parts 
to the remaining parts in terms of 
shape and level of wear – rework 
accordingly
Carbide-tipped (Duro) saw chains are 
especially wear-resistant. For an optimal 
sharpening result, STIHL recommends 
STIHL servicing dealers.
WARNING
Compliance with the angles and 
dimensions listed below is absolutely 
necessary. An improperly sharpened 
saw chain – especially depth gauges 
that are too low – can lead to increased 
kickback tendency of the chain saw – 
risk of injury!
Chain pitch
The chain pitch marking (a) is embossed 
in the area of the depth gauge of each 
cutter.
The diameter of file to be used depends 
on the chain pitch – see table 
"Sharpening tools".
The angles of the cutter must be 
maintained during resharpening.Sharpening and side plate angles
ASharpening angle
STIHL saw chains are sharpened with a 
30° sharpening angle. Ripping chains, 
which are sharpened with a 10° 
sharpening angle, are exceptions. 
Ripping chains have an X in the 
designation.
BSide plate angle
The correct side plate angle results 
automatically when the specified file 
holder and file diameter are used.
The angles must be identical for all 
cutters in the saw chain. Varying angles: 
Rough, uneven running of the saw 
chain, increased wear – even to the 
point of saw chain breakage.Maintaining and Sharpening 
the Saw Chain
Marking (a)Chain pitch
Inches mm
71/4P6.35
1 or 1/4 1/4 6.35
6, P or PM 3/8 P 9.32
2 or 325 0.325 8.25
3 or 3/8 3/8 9.32
4 or 404 0.404 10.26
689BA027 KN
a
7RRWKVKDSHV $QJOHr
$%
0LFUR VHPLFKLVHOWRRWK
H J 30 50
 50 
6XSHU IXOOFKLVHOWRRWK
H J 36 56
 56 
5LSSLQJFKDLQH J
 30; 50; 
A
B
689BA021 KN 
						

							MS 241 C-M
English
45
File holder
NUse a file holder
Always use a file holder (special 
accessory, see table "Sharpening tools") 
when sharpening saw chains by hand. 
File holders have markings for the 
sharpening angle.
Use only special saw chain files! Other 
files are unsuitable in terms of shape 
and type of cutting.
To check the angles
STIHL filing gauge (special accessory, 
see table "Sharpening tools") – a 
universal tool for checking sharpening 
and side plate angles, depth gauge 
setting, and tooth length, as well as 
cleaning grooves and oil inlet holes.
Proper sharpening
NSelect sharpening tools in 
accordance with chain pitch
NClamp guide bar if necessary
NBlock saw chain – push the hand 
guard forward
NTo advance the saw chain, pull the 
hand guard toward the handlebar: 
The chain brake is disengaged. 
With the Quickstop Plus chain brake 
system, additionally press the 
throttle trigger lockout
NSharpen frequently, removing little 
m a t e r i a l  –  t w o  o r  t h r e e  s t r o k e s  o f  t h e  
file are usually sufficient for simple 
resharpening
NGuide the file: horizontally ( a t  a  r i g h t  
angle to the side surface of the 
guide bar) in accordance with the 
specified angle – according to the markings on the file holder – rest the 
file holder on the tooth head and the 
depth gauge
NFile only from the inside outward
NThe file only sharpens on the 
forward stroke – lift the file on the 
backstroke
NDo not file tie straps and drive links
NRotate the file a little periodically in 
order to avoid uneven wear
NTo remove file burr, use a piece of 
hardwood
NCheck angle with file gauge
All cutters must be equally long.
With varying cutter lengths, the cutter 
heights also vary and cause rough 
running of the saw chain and chain 
breakage.
NAll cutters must be filed down equal 
to the length of the shortest cutter – 
ideally, one should have this done 
by a servicing dealer using an 
electric sharpener
Depth gauge setting
The depth gauge determines the depth 
to which the cutter penetrates the wood 
and thus the chip thickness.
689BA025 KN
001BA203 KN
689BA018 KN
90°
689BA043 KN
689BA023 KN
a 
						

							MS 241 C-M
English
46 aRequired distance between depth 
gauge and cutting edge
When cutting softwood outside of the 
frost season, the distance can be 
increased by up to 0.2 mm (0.008").
Lowering the depth gauges
The depth gauge setting is lowered 
when the cutter is sharpened.
NCheck the depth gauge setting after 
each sharpening
NLay the appropriate file gauge (1) 
for the chain pitch on the saw chain 
and press it against the cutter to be 
checked – if the depth gauge 
protrudes past the file gauge, the 
depth gauge must be reworkedSaw chains with humped drive link (2) – 
upper part of the humped drive link (2) 
(with service mark) is lowered at the 
same time as the depth gauge of the 
cutter.
WARNING
The rest of the humped drive link must 
not be filed; otherwise, this could 
increase the tendency of the chain saw 
to kick back.
NR e w o r k  t h e  d e p t h  g a u g e  s o  t h a t  i t  i s  
flush with the file gauge
NAfterwards, dress the leading edge 
of the depth gauge parallel to the 
service mark (see arrow) – when 
doing this, be careful not to further 
lower the highest point of the depth 
gauge
WARNING
Depth gauges that are too low increase 
the kickback tendency of the chain saw.
NLay the file gauge on the saw chain 
– the highest point of the depth 
gauge must be flush with the file 
gauge
NAfter sharpening, clean the saw 
chain thoroughly, removing any 
filings or grinding dust – lubricate 
the saw chain thoroughly
NIn the event of extended periods of 
disuse, store saw chains in cleaned 
and oiled condition Chain pitch Depth gauge
Distance (a)
Inches (mm) mm (Inches)
1/4 P (6.35) 0.45 (0.018)
1/4 (6.35) 0.65 (0.026)
3/8 P (9.32) 0.65 (0.026)
0.325 (8.25) 0.65 (0.026)
3/8 (9.32) 0.65 (0.026)
0.404 (10.26) 0.80 (0.031)
2
689BA061 KN
1
689BA051 KN
689BA044 KN
689BA052 KN 
						

							MS 241 C-M
English
47 Sharpening tools (special accessories)
Chain pitch Round file ^Round file File holder File gaugeTaper square file Sharpening set 
1)
Inches (mm) mm (Inches) Part number Part number Part number Part number Part number
1/4 P (6.35) 3.2 (1/8) 5605 771 32065605 750 4300 0000 893 4005 0814 252 3356 5605 007 1000
1/4 (6.35) 4.0 (5/32) 5605 772 40065605 750 4327 1110 893 4000 0814 252 3356 5605 007 1027
3/8 P (9.32) 4.0 (5/32) 5605 772 4006 5605 750 4327 1110 893 4000 0814 252 3356 5605 007 1027
0.325 (8.25) 4.8 (3/16) 5605 772 4806 5605 750 4328 1110 893 4000 0814 252 3356 5605 007 1028
3/8 (9.32) 5.2 (13/64) 5605 772 5206 5605 750 4329 1110 893 4000 0814 252 3356 5605 007 1029
0.404 (10.26) 5.5 (7/32) 5605 772 5506 5605 750 4330 1106 893 4000 0814 252 3356 5605 007 1030
1)consisting of file holder with round file, taper square file and file gauge 
						

							MS 241 C-M
English
48
Maintenance and Care
The following information applies in normal operating conditions. The specified inter-
vals must be shortened accordingly when working for longer than normal or under 
difficult cutting conditions (extensive dust, highly resinous lumber, lumber from trop-
ical trees, etc.). If the machine is only used occasionally, the intervals can be 
extended accordingly.
Before starting work
At the end of work and/or 
daily
Whenever tank is refilled
Weekly
Monthly
Yearly
If faulty
If damaged
As required
Complete machineVisual inspection (condition, leaks)XX
CleanX
Throttle trigger, throttle trigger lockout, 
choke lever, choke control, stop switch, 
master control lever (dependent on 
equipment)Function testsXX
Chain brakeFunction testsXX
Have checked by a specialist dealer
1)X
Manual fuel pump (if present)CheckX
Have repaired by a specialist dealer
1)X
Fuel pick-up body / filter in fuel tankCheckX
Clean, replace filter insertXX
ReplaceXXX
Fuel tank CleanX
Lubricating oil tank CleanX
Chain lubrication CheckX
Saw chainCheck, pay attention to sharpnessXX
Check chain tensionXX
SharpenX
Guide barCheck (wear, damage)X
Clean and turn overX
DeburrX
ReplaceXX
Chain sprocket CheckX