Stihl 181 C Manual

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
39 at the same time and hold them in that 
position – now set the Master Control 
lever.
To select the starting throttle 
position (n), move the Master Control 
lever to choke closed (l) first, then 
push it into the starting throttle 
position (n).
The Master Control lever must be in the 
choke closed position (l) before it can 
be moved to to the starting throttle 
position (n).
The Master Control lever moves from 
the starting throttle position (n) to the 
normal run position (F) when you press 
down the throttle lockout and blip the 
throttle trigger at the same time.
To switch off the engine, move the 
Master Control lever to Stop0. 
Choke shutter closed (l)
–if the engine is cold 
–If the engine stalls when you open 
the throttle after starting.
–If the fuel tank was run until empty 
(engine stopped).
Starting throttle position (n)
–If the engine is warm, i.e. if it has 
been running for about one minute.
–When the engine begins to fire.
–After clearing a flooded combustion 
chamber. 
Fuel pump
Press the fuel pump bulb several times – 
even if the bulb is already filled with fuel: 
–When starting for the first time.
–If the fuel tank was run until empty 
(engine stopped).
Holding the saw
There are two ways of holding the saw 
when starting.On the ground 
NPlace your saw on the ground. 
Make sure you have a firm footing – 
check that the chain is not touching 
any object or the ground.
NHold the saw firmly on the ground 
with your left hand on the front 
handle – your thumb should be 
under the handle.
NPut your right foot into the rear 
handle and press down.
143BA018 KN 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
40 Between knees or thighs
NHold the rear handle tightly between 
your legs, just above the knees.
NHold the front handle firmly with 
your left hand – your thumb should 
be under the handle.
Starting
Standard versions
NPull the starter grip slowly with your 
right hand until you feel it engage – 
and then give it a brisk strong pull 
and push down the front handle at 
the same time. Do not pull out the 
starter rope to full length – it might 
otherwise break. Do not let the 
starter grip snap back. Guide it 
slowly back into the housing so that 
the starter rope can rewind properly. 
Machines without additional manual fuel 
pump: If the engine is new or after a long 
out-of-service period, it may be 
necessary to pull the starter rope several 
times to prime the fuel system.Versions with Easy2Start
The Easy2Start stores the energy 
required to start the saw. For this reason 
there may be a delay of a few seconds 
between cranking the engine and it 
actually starting.
There are two ways of starting machines 
with Easy2Start:
NHold the starter grip with your right 
hand and pull it out slowly and 
steadily – or – hold the starter grip 
with your right hand and give it 
several short pulls, using only a 
short length of rope for each pull.
NPush down the handle while 
cranking. Do not pull out the rope to 
its full length – it might otherwise 
break.
NDo not let the starter grip snap back. 
Guide it slowly back into the housing 
so that the starter rope can rewind 
properly.
Starting the saw
WARNING
Bystanders must be well clear of the 
general work area of the saw.
NObserve safety precautions.
143BA019 KN
143BA020 KN 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
41 Versions with manual fuel pump
NPress the fuel pump bulb at least 
five times – even if the bulb is 
already filled with fuel.All models
NPush the hand guard (1) forward – 
the chain is locked.
NPress down trigger lockout (2) and 
pull the throttle trigger at the same 
time. Set Master Control lever (3) to:
Choke shutter closed (l)
–If the engine is cold (also use this 
position if the engine stopped when 
you opened the throttle after 
starting) 
Starting throttle position (n)
–If the engine is warm, i.e. if it has 
been running for about one minute.
NHold and start your saw as 
described. 
When the engine begins to fire:
NSet the Master Control lever to the 
starting throttle position (n ).
NHold and start your saw as 
described. 
As soon as the engine runs
NPress down the trigger lockout and 
the blip the throttle trigger (4) – the 
Master Control lever (3) moves to 
the run positionF and the engine 
settles down to idling speed.
533BA004 KN
2
1
533BA005 KN
0
3
3
4
5
0
533BA006 KN 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
42 NPull the hand guard back toward the 
front handle.
The chain brake is now disengaged – 
your saw is ready for operation.
NOTICE
Always disengage chain brake before 
accelerating the engine. High revs with 
the chain brake engaged (chain locked) 
will quickly damage the clutch and chain 
brake.
At very low outside temperatures:
NAllow engine to warm up at part 
throttle.
Stopping the engine
NMove the Master Control lever to the 
stop position (0).
If the engine does not start
If you did not move the Master Control 
lever from the choke shutter closed 
position (l) to the starting throttle 
position (n) quickly enough, the engine 
may be flooded.
NMove the Master Control lever to the 
stop position (0).
NRemove the spark plug – see 
"Spark Plug".
NDry the spark plug.
NCrank the engine several times with 
the starter to clear the combustion 
chamber.
NRefit the spark plug – see "Spark 
Plug".
NSet Master Control lever to the 
starting throttle position (n) – even 
if the engine is cold.
NNow start the engine.
During the break-in period
A factory new machine should not be run 
at high revs (full throttle off load) for the 
first three tank fillings. This avoids 
unnecessarily high loads during the 
break-in period. As all moving parts 
have to bed in during the break-in 
period, the frictional resistances in the 
shortblock are greater during this period. 
The engine develops its maximum 
power after about 5 to 15 tank fillings.
During work
NOTICE
Do not make the mixture leaner to 
achieve an apparent increase in power – 
this could damage the engine – see 
"Adjusting the Carburetor".
NOTICE
Open the throttle only when the chain 
brake is off. Running the engine at high 
revs with the chain brake engaged 
(chain locked) will quickly damage the 
shortblock and chain drive (clutch, chain 
brake).
Check chain tension frequently
A new saw chain must be retensioned 
more frequently than one that has been 
in use already for an extended period.
143BA012 KN
2SHUDWLQJ,QVWUXFWLRQV 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
43 Chain cold
Tension is correct when the chain fits 
snugly against the underside of the bar 
but can still be pulled along the bar by 
hand. Retension if necessary – see 
"Tensioning the Saw Chain".
Chain at operating temperature
The chain stretches and begins to sag. 
The drive links must not come out of the 
bar groove on the underside of the bar – 
the chain may otherwise jump off the 
bar. Retension the chain – see 
"Tensioning the Saw Chain".
NOTICE
The chain contracts as it cools down. If it 
is not slackened off, it can damage the 
crankshaft and bearings.
After a long period of full-throttle 
operation
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 components (ignition, 
carburetor) from thermal overload.
After finishing work
NSlacken 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.
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.
Long-term storage
See "Storing the machine"
NTurn 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.
NRegularly clean the oil inlet hole (1), 
the oilway (2) and the bar groove 
(3).
NMeasure the groove depth – with the 
scale on the filing gauge (special 
accessory) – in the area used most 
for cutting.
Taking Care of the Guide Bar
Chain 
typeChain pitch Minimum 
groove depth
Picco 1/4" P 0.16" (4.0 mm)
Rapid 1/4" 0.16" (4.0 mm)
2
3 1
143BA026 KN 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
44 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
NSqueeze the throttle trigger and 
move the Master Control lever to l 
.
NSlide the lock to the rear.
NRemove the shroud upwards to the 
rear.
Installing the shroud
NRefit the shroud and secure it with 
the lock.The air filter system can be adapted to 
suit different operating conditions by 
installing a choice of filters. Changing 
the filter is quick and simple.
Fleece mat (MS 171)
Top illustration.
One-piece fleece filter with sealing lip 
(MS 181, MS 211)
Bottom illustration, special accessory on 
MS 171. 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
533BA002 KN
$LU)LOWHU6\VWHP
533BA008 KN 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
45 One-piece fabric filter (special 
accessory)
For damp and extremely cold operating 
conditions.If there is a noticeable loss of engine 
power
NRemove the shroud – see "Shroud".
NAlways replace damaged filters.
NClean away loose dirt from around 
the filter.
NPush the two locking tabs upwards, 
tilt the air filter towards the rear 
handle and remove.
NOTICE
To avoid damaging the filter, do not use 
tools for removing and installing the air 
filter.
NBlow out the filter with compressed 
air from the clean air side.
If the filter fabric is caked with dirt or no 
compressed air is available:
NWash the filter in a clean, non-
flammable solution (e.g. warm 
soapy water) and then dry.
NReinstall the air filter.
NInstall 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.
Cleaning the Air Filter
533BA009 KN
(QJLQH0DQDJHPHQW 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
46
General Information
The carburetor comes from the factory 
with a standard setting.
This setting provides an optimum fuel-air 
mixture under most operating 
conditions.
Preparations
NShut off the engine.
NCheck the air filter and clean or 
replace if necessary.
NCheck the spark arresting screen 
(not in all models, country-specific) 
in the muffler and clean or replace if 
necessary.
Standard Setting
NTurn high speed screw (H) 
counterclockwise as far as stop (no 
more than 3/4 turn).
NTurn the low speed screw (L) 
clockwise as far as stop, then turn it 
back 1/4 turn.
Adjusting Idle Speed
NCarry out the standard setting.
NStart and warm up the engine.
Engine stops while idling
NTurn the idle speed screw (LA) 
clockwise until the chain begins to 
run – then back it off 2 turns.
Saw chain runs while engine is idling
NTurn the idle speed screw (LA) 
counterclockwise until the chain 
stops moving – then turn it another 
2 turns in the same direction.
WARNING
If the chain continues moving when the 
engine is idling, have your saw checked 
and repaired by your servicing dealer.
Erratic idling behavior, poor acceleration 
(even though standard setting of low 
speed screw is correct)
Idle setting is too lean
NTurn the low speed screw (L) 
carefully counterclockwise, no 
further than stop, until the engine 
runs smoothly and accelerates well.It is usually necessary to change the 
setting of the idle speed screw (LA) after 
every correction to the low speed 
screw (L).
Fine Tuning for Operation at High 
Altitude
A slight correction of the setting may be 
necessary if the engine does not run 
satisfactorily:
NCarry out the standard setting.
NWarm up the engine.
NTurn high speed screw (H) slightly 
clockwise (leaner) – no further than 
stop.
NOTICE
After returning from high altitude, reset 
the carburetor to the standard setting.
If the setting is too lean there is a risk of 
engine damage due to insufficient 
lubrication and overheating.
Adjusting the Carburetor
HL
533BA020 KN
LA
L
533BA021 KN 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
47
Spark arresting screen in muffler
NIf the engine is down on power, 
check the spark arresting screen in 
the muffler.
STIHL recommends that you have 
servicing and repair work carried out 
exclusively by an authorized STIHL 
servicing dealer.If the engine is down on power, difficult 
to start or runs poorly at idling speed, 
first check the spark plug.
Install a new spark plug after approx. 
100 operating hours or earlier if the 
electrodes are badly eroded/corroded.
The 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 degrade performance.
Removing the spark plug
NRemove the shroud – see "Shroud".
NPull off the spark plug boot.
NUnscrew the spark plug.
Checking the spark plug
NClean the spark plug if it is dirty
NCheck the electrode gap (A) and 
readjust if necessary – see 
"Specifications"
NUse only resistor type spark plugs of 
the approved range
Correct the problems that have caused 
fouling of the spark plug:
–too much oil in fuel mix,
–dirty air filter,
–unfavorable running conditions, e.g. 
operating at part throttle.Spark Arresting Screen in 
MufflerSpark Plug
533BA007 KN
000BA039 KNA 
						

							MS 171, MS 181, MS 181 C, MS 211, MS 211 C
English
48
WARNING
To reduce the risk of fire and burn injury, 
use only spark plugs authorized by 
STIHL. Always press the spark plug 
boot (1) snugly onto the spark plug 
terminal (2).
Do not use a spark plug with a 
detachable SAE adapter terminal (3). 
Arcing may occur that could ignite 
combustible fumes and cause a fire. 
This can result in serious injuries or 
damage to property. 
NOnly use resistor type spark plugs 
with solid, non-threaded terminals
Installing the spark plug
NInstall the spark plug and connect 
the spark plug boot (press it down 
firmly) – reassembly all other parts 
in the reverse sequence.If engine running behavior is 
unsatisfactory even though the air filter 
is clean and the carburetor is properly 
adjusted, the cause may be the muffler.
Have the muffler checked for 
contamination (carbonization) by your 
servicing dealer.
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.
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