Stihl Ms 250 C Manual

							{
STIHL MS 250
WARNING To reduce the risk of 
kickback injury use STIHL reduced kickback bar 
and STIHL low kickback chain as specified in 
this manual or other available low kickback 
components.
ADVERTENCIA Para reducir el 
riesgo de lesionarse como resultado de un 
culatazo, utilice la barra y la cadena de 
contragolpe reducido de la forma especificada 
en este manual o de otros componentes 
reductores de contragolpe.
Read Instruction Manual thoroughly before 
use and follow all safety precautions – 
improper use can cause serious or fatal injury.Antes de usar la máquina lea y siga todas las precauciones 
de seguridad dadas en el manual de instrucciones – el uso 
incorrecto puede causar lesiones graves o mortales.
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							Instruction Manual
1 - 58
Manual de instrucciones
59 - 122 
						

							Original Instruction Manual Printed on chlorine-free paper
Printing inks contain vegetable oils, paper can be recycled. © ANDREAS STIHL AG & Co. KG, 2017
0458-208-8621-B. VA2.F17. 
0000001880_019_GB
MS 250
English
1
{This instruction manual is protected by copyright. All rights reserved, especially the rights to reproduce, translate and process 
with electronic systems.
Contents
Allow only persons who fully understand 
this manual to operate your chain saw.
To receive maximum performance and 
satisfaction from your STIHL chain saw, 
it is important that you read, understand 
and follow the safety precautions and 
the operating and maintenance 
instructions in chapter "Safety 
Precautions and Working Techniques" 
before using your chain saw. For further 
information you can go to 
www.stihlusa.com.
Contact your STIHL dealer or the STIHL 
distributor for your area if you do not 
understand any of the instructions in this 
manual.
WARNING
Because a chain saw is a high-speed 
wood-cutting tool, some special safety 
precautions must be observed as with 
any other power saw to reduce the risk 
of personal injury. Careless or improper 
use may cause serious or even fatal 
injury. Guide to Using this Manual 2
Safety Precautions and Working 
Techniques 3
Cutting Attachment 26
Mounting the Bar and Chain 26
Tensioning the Chain 27
Checking Chain Tension 28
Fuel 28
Fueling 29
Chain Lubricant 31
Filling Chain Oil Tank 32
Checking Chain Lubrication 32
Chain Brake 33
Winter Operation 34
Starting / Stopping the Engine 34
Operating Instructions 38
Taking Care of the Guide Bar 39
Air Filter System 40
Cleaning the Air Filter 40
Engine Management 41
Adjusting the Carburetor 41
Spark Plug 42
Engine Running Behavior 44
Storing the Machine 44
Checking and Replacing the Chain 
Sprocket 44
Maintaining and Sharpening the 
Saw Chain 45
Maintenance and Care 49
Main Parts 51
Specifications 53
Ordering Spare Parts 54Maintenance and Repairs 54
Disposal 54
Limited Warranty 55
STIHL Incorporated Federal 
Emission Control Warranty 
Statement 55
Trademarks 57 
						

							MS 250
English
2 This Instruction Manual refers to a 
STIHL chain saw, also called a machine 
in this Instruction Manual.
Pictograms
The meanings of the pictograms 
attached to or embossed on the 
machine are explained in this manual.
Depending on the model concerned, the 
following pictograms may be on your 
machine.
Symbols in Text
Many operating and safety instructions 
are supported by illustrations.
The individual steps or procedures 
described in the manual may be marked 
in different ways:
NA bullet marks a step or procedure.
A description of a step or procedure that 
refers directly to an illustration may 
contain item numbers that appear in the 
illustration. Example:
NLoosen the screw (1).
NLever (2) ...
In addition to the operating instructions, 
this manual may contain paragraphs 
that require your special attention. Such 
paragraphs are marked with the 
symbols and signal words described 
below:
DANGER
Indicates a hazardous situation that, if 
not avoided, will result in death or 
serious injury.
WARNING
Indicates a hazardous situation that, if 
not avoided, could result in death or 
serious injury.
NOTICE
Indicates a risk of property damage, 
including damage to the machine or its 
individual components.
Engineering Improvements
STIHL’s philosophy is to continually 
improve all of its products. As a result, 
engineering changes and improvements 
are made from time to time. Therefore, 
some changes, modifications and 
improvements may not be covered in 
this manual. If the operating 
characteristics or the appearance of 
your machine differs from those 
described in this manual, please contact 
your STIHL dealer or the STIHL 
distributor for your area for assistance.
Guide to Using this Manual
Fuel tank; fuel mixture of 
gasoline and engine oil
Chain oil tank; chain oil
Engaging and disengag-
ing the STIHL Quickstop 
chain brake
Direction of chain rotation
Ematic; chain oil quantity 
control
Tension the chain
Intake air preheating for 
winter operation
Intake air for summer 
operation
Handle heating
Operate decompression 
valve
Operate manual fuel 
pump 
						

							MS 250
English
3
WARNING
The use of this chain saw may be 
hazardous. The saw chain has many 
sharp cutters. If the cutters contact your 
flesh, they will cut you, even if the chain 
is not moving. 
WARNING
Reactive forces, including kickback, can 
be dangerous. Pay special attention to 
the section on reactive forces.
Have your STIHL dealer show you how 
to operate your chain saw. All safety 
precautions that are generally observed 
when working with an axe or a hand saw 
also apply to the operation of chain 
saws. Observe all applicable federal, 
state and local safety regulations, 
standards and ordinances. When using a chain saw for logging purposes, for 
instance, refer to the OSHA regulations 
for "logging operations" at 29 Code of 
Federal Regulations 1910.266.
WARNING
Do not lend or rent your chain saw 
without the instruction manual. Be sure 
that anyone using it understands the 
information contained in this manual.
The use of noise emitting chain saws 
may be restricted to certain times by 
national, state or local regulations.
Use your chain saw only for cutting 
wooden objects.
WARNING
Do not use it for other purposes, since 
misuse may result in personal injury or 
property damage, including damage to 
the chain saw.
WARNING
Minors should never be allowed to use 
this chain saw. Bystanders, especially 
children, and animals should not be 
allowed in the area where it is in use.
Most of these safety precautions and 
warnings apply to the use of all STIHL 
chain saws. Different models may have 
different parts and controls. See the 
appropriate section of your instruction 
manual for a description of the controls 
and the function of the parts of your 
model.
WARNING
Always stop the engine and activate the 
QuickStop Chainbrake before 
transporting or carrying out any work on 
the chain saw. This avoids the risk of the 
engine starting unintentionally.
STIHL recommends the use of genuine 
STIHL replacement parts. They are 
specifically designed to match your 
model and meet your performance 
requirements.
Safe use of a chain saw involves
1the operator
2the chain saw
3the use of the chain saw.
THE OPERATOR
Physical Condition
You must be in good physical condition 
and mental health and not under the 
influence of any substance (drugs, 
alcohol, etc.) which might impair vision, 
dexterity or judgment. Do not operate 
this chain saw when you are fatigued.
WARNING
Be alert – if you get tired, take a break. 
Tiredness may result in loss of control. 
Working with any power tool can be 
strenuous. If you have any condition that 
might be aggravated by strenuous work, 
check with your doctor before operating 
this chain saw.
Safety Precautions and 
Working Techniques
Because a chain saw is a 
high-speed, fast-cutting 
power tool, special safety 
precautions must be 
observed to reduce the 
risk of personal injury.
It is important that you 
read, fully understand 
and observe the following 
safety precautions and 
warnings. Read the 
instruction manual and 
the safety instructions 
periodically. Careless or 
improper use may cause 
serious or fatal injury. 
Save the instruction man-
ual for future reference. 
						

							MS 250
English
4
WARNING
Prolonged use of a chain saw (or other 
power tools) exposing the operator to 
vibrations may produce whitefinger 
disease (Raynaud's phenomenon) or 
carpal tunnel syndrome.
These conditions reduce the hand's 
ability to feel and regulate temperature, 
produce numbness and burning 
sensations and may cause nerve and 
circulation damage and tissue necrosis.
All factors which contribute to white-
finger disease are not known, but cold 
weather, smoking and diseases or 
physical conditions that affect blood 
vessels and blood transport, as well as 
high vibration levels and long periods of 
exposure to vibration are mentioned as 
factors in the development of whitefinger 
disease. In order to reduce the risk of 
whitefinger disease and carpal tunnel 
syndrome, please note the following:
–Most STIHL chain saws are 
available with an anti-vibration 
("AV") system designed to reduce 
the transmission of vibrations 
created by the chain saw to the 
operator's hands. An AV system is 
recommended for those persons 
using chain saws on a regular or 
sustained basis.
–Wear gloves and keep your hands 
warm. Heated handles, which are 
available on some STIHL chain 
saws, are recommended for cold 
weather use.–Keep the AV system well 
maintained. A chain saw with loose 
components or with damaged or 
worn AV elements will tend to have 
higher vibration levels.
–Keep the saw chain sharp and well 
maintained. A dull saw chain will 
increase cutting time, and pressing 
a dull saw chain through wood will 
increase the vibrations transmitted 
to your hands.
–Maintain a firm grip at all times, but 
do not squeeze the handles with 
constant, excessive pressure. Take 
frequent breaks.
All the above-mentioned precautions do 
not guarantee that you will not sustain 
whitefinger disease or carpal tunnel 
syndrome. Therefore, continual and 
regular users should closely monitor the 
condition of their hands and fingers. If 
any of the above symptoms appear, 
seek medical advice immediately.
WARNING
The ignition system of the STIHL unit 
produces an electromagnetic field of a 
very low intensity. This field may 
interfere with some pacemakers. To 
reduce the risk of serious or fatal injury, 
persons with a pacemaker should 
consult their physician and the 
pacemaker manufacturer before 
operating this chain saw.
Proper Clothing
WARNING
To reduce the risk of injury, the operator 
should wear proper protective apparel.Clothing must be sturdy 
and snug-fitting, but allow 
complete freedom of 
movement.To reduce the 
risk of cut injuries, wear 
the type of overalls, long 
pants or chaps that con-
tain pads of cut-retardant 
material. Avoid loose-fit-
ting jackets, scarfs, 
neckties, jewelry, flared 
or cuffed pants, uncon-
fined long hair or 
anything that could 
become caught on 
branches, brush or the 
moving parts of the chain 
saw. Secure hair so it is 
above shoulder level..
Good footing is very 
important. Wear sturdy 
boots with nonslip soles. 
Steel-toed safety boots 
are recommended. Never 
wear sandals, flip-flops or 
go barefoot.
Always wear heavy-duty 
work gloves (e.g. made of 
leather or wear resistant 
material) when handling 
the chain saw and the 
cutting tool. Heavy-duty, 
nonslip gloves improve 
your grip and help to pro-
tect your hands. 
						

							MS 250
English
5 Be particularly alert and cautious when 
wearing hearing protection because 
your ability to hear warnings (shouts, 
alarms, etc.) is restricted.
THE CHAIN SAW
For illustrations and definitions of the 
chain saw parts see the chapter on 
"Main Parts."
WARNING
Never modify this chain saw in any way. 
Only attachments supplied by STIHL or 
expressly approved by STIHL for use 
with the specific STIHL model are 
authorized. Although certain 
unauthorized attachments are useable 
with STIHL chain saws, their use may, in 
fact, be extremely dangerous.
WARNING
Never operate your chain saw if it is 
damaged, improperly adjusted or 
maintained, or not completely or 
securely assembled.
If this chain saw is subjected to 
unusually high loads for which it was not 
designed (e.g. heavy impact or a fall), 
always check that it is in good condition 
before continuing work. Check in 
particular that the fuel system is tight (no 
leaks) and that the controls and safety 
devices are working properly. Do not 
continue operating this chain saw if it is 
damaged. In case of doubt, have it 
checked by your STIHL servicing dealer.
THE USE OF THE CHAIN SAW
Transporting the Chain Saw
WARNING
Always stop the engine before putting 
the chain saw down. Carrying a chain 
saw with the engine running may be 
extremely dangerous.Accidental acceleration of the engine 
can cause the saw chain to rotate. 
Always engage the chain brake when 
taking more than a few steps.
By hand: When transporting your chain 
saw by hand, the engine must be shut 
off and the chain saw must be in the 
proper position, i.e., grip the top handle 
and place the muffler away from the 
body; the chain guard (scabbard) should 
be over the saw chain and guide bar, 
which should point backwards, away 
from the direction in which you are 
walking.
By vehicle: When transporting in a 
vehicle, keep saw chain and bar covered 
with the chain guard (scabbard). 
Properly secure your chain saw to 
prevent turnover, fuel spillage and 
damage to the chain saw. To reduce the risk of 
injury to your eyes never 
operate your power tool 
unless wearing goggles 
or properly fitted protec-
tive glasses with 
adequate top and side 
protection complying with 
ANSI Z87 "+" (or your 
applicable national stand-
ard). If there is a risk of 
injury to your face, STIHL 
recommends that you 
also wear a face shield or 
face screen over your 
goggles or protective 
glasses.
Wear an approved safety 
hard hat  to reduce the 
risk of injury to your head. 
Chain saw noise may 
damage your hearing. 
Wear sound barriers (ear 
plugs or ear mufflers) to 
help protect your hearing. 
Continual and regular 
users should have their 
hearing checked 
regularly.
001BA275 KN 
						

							MS 250
English
6 Fuel
Your STIHL chain saw uses an oil- 
gasoline mixture for fuel (see the 
chapter on "Fuel" of your instruction 
manual).
WARNING
Fueling Instructions
WARNING
Fuel your chain saw in well-ventilated 
areas, outdoors. Always shut off the 
engine and allow it to cool before 
refueling. Gasoline vapor pressure may 
build up inside the fuel tank depending 
on the fuel used, the weather conditions 
and the tank venting system.
In order to reduce the risk of burns and 
other personal injury from escaping gas 
vapor and fumes, remove the fuel filler 
cap on your chain saw carefully so as to 
allow any pressure build-up in the tank 
to release slowly.Flip up the lever and slowly turn left (1) 
to the vent position of the cap at about 
1/8 turn where the cap is held in place by 
the thread. Once the fumes have been 
relieved, turn (2) the cap further to the 
1/4 turn position where the tool-less cap 
can be removed from the tank thread.
Never remove the fuel filler cap by 
quickly turning it to the full 1/4 open 
position without letting it vent out any 
vapor/pressure build-up at the 
1/8 position.
Never remove the fuel filler cap while the 
engine is running.
Select bare ground for fueling and move 
at least 10 feet (3 m) from the fueling 
spot before starting the engine. Wipe off 
any spilled fuel before starting your 
chain saw.
WARNING
Different models may be equipped with 
different fuel caps.
Toolless cap with grip
WARNING
In order to reduce the risk of fuel spillage 
and fire from an improperly tightened 
fuel cap, correctly position and tighten 
the fuel cap in the fuel tank opening.
To do this with this STIHL cap, raise the 
grip on the top of the cap until it is upright 
at a 90° angle. Insert the cap in the fuel 
tank with the positioning mark on the 
grip of the cap and the "open" mark on 
the fuel tank opening lining up. Using the 
grip, press the cap down firmly while 
turning it clockwise as far as it will go  Gasoline is an extremely 
flammable fuel. If spilled 
and ignited by a spark or 
other ignition source, it 
can cause fire and seri-
ous burn injury or 
property damage. Use 
extreme caution when 
handling gasoline or fuel 
mix. Do not smoke or 
bring any fire or flame 
near the fuel or the chain 
saw. Note that combus-
tible fuel vapor may 
escape from the fuel 
system.
2
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001BA234 KN 
						

							MS 250
English
7 (approx. 1/4 turn). The positioning mark 
on the cap should now line up with the 
"closed" mark on the tank.
Misaligned, damaged or broken cap
NIf the cap does not drop fully into the 
opening when the positioning marks 
line up and/or if the cap does not 
tighten properly when twisted, the 
base of the cap may be prematurely 
rotated (in relation to the top) to the 
closed position. Such misalignment 
can result from handling, cleaning 
or an improper attempt at 
tightening.NTo return the cap to the open 
position for installation, turn the cap 
(with the grip up) until it drops fully 
into the tank opening. Next, twist the 
cap counterclockwise as far as it will 
go (approx. 1/4 turn) – this will twist 
the base of the cap into the correct 
position for installation. Then, twist 
the cap clockwise, closing it 
normally.
NIf your cap still does not tighten 
properly, it may be damaged or 
broken; immediately stop use of the 
unit and take it to your authorized 
STIHL dealer for repair.See also the "Fueling" chapter in your 
Instruction Manual for additional 
information.
Before Operation
Take off the chain guard (scabbard) and 
inspect the chain saw for proper 
condition and operation. (See the 
maintenance chart near the end of the 
instruction manual.)
WARNING
A l w a y s  c h e c k  y o u r  c h a i n  s a w   f o r  p r o p e r  
condition and operation before starting, 
particularly the throttle trigger, throttle 
trigger lockout, stop switch and cutting 
attachment. The throttle trigger must 
move freely and always spring back to 
the idle position. The Master Control 
Lever / stop switch must move easily to 
STOP, 0 or †. Never attempt to modify 
the controls or safety devices.
WARNING
Check fuel system for leaks, especially 
the visible parts, e.g., filler cap, hose 
connections, manual fuel pump (only for 
chain saws equipped with a manual fuel 
pump). Do not start the engine if there 
are leaks or damage – risk of fire! Have 
the chain saw repaired by a STIHL 
servicing dealer before using it.
WARNING
Check that the spark plug boot is 
securely mounted on the spark plug – a 
loose boot may cause arcing that could 
ignite combustible fumes and cause a 
fire. Fold the grip flush with 
the top of the cap. Grip 
the cap and check for 
tightness. If the grip does 
not lie completely flush 
with the cap and the 
detent on the grip does 
not fit in the correspond-
ing recess in the filler 
opening, or if the cap is 
loose in the filler opening, 
the cap is not properly 
seated and tightened and 
you must repeat the 
above steps.
Left: Bottom of cap in closed posi-
tion – inner mark (1) in line 
with outer mark.
Right: Bottom of cap in correct posi-
tion for installation – inner 
mark is under the grip and 
not in line with the outer 
mark.
1
001BA238 KN
001BA239 KN 
						

							MS 250
English
8 For proper assembly of the bar and saw 
chain follow the procedure described in 
the chapter "Mounting the Bar and 
Chain" of your instruction manual. 
STIHL Oilomatic saw chain, guide bar 
and sprocket must match each other in 
gauge and pitch. Before replacing any 
bar and chain, see the chapter entitled 
"Specifications" in the instruction 
manual and the chapter "Reactive 
Forces including Kickback".
Since longer bars add weight and may 
be more difficult to control, select the 
shortest bar that will meet your cutting 
needs.
WARNING
Proper tension of the chain is extremely 
important. In order to avoid improper 
setting, the tensioning procedure must 
be followed as described in your 
manual. Always make sure the 
hexagonal nut(s) for the sprocket cover 
is (are) tightened securely after 
tensioning the saw chain in order to 
secure the bar. Never start the chain 
saw with the sprocket cover loose. 
Check chain tension once more after 
having tightened the nut(s) and 
thereafter at regular intervals (whenever 
the saw is shut off). If the saw chain 
becomes loose while cutting, shut off the 
engine and then tighten. Never try to 
adjust the saw chain while the engine is 
running!
WARNING
After adjusting a saw chain, start the 
chain saw, let the engine run for a while, 
then switch engine off and recheck saw 
chain tension. Proper saw chain tension 
is very important at all times.Keep the handles clean and dry at all 
times; it is particularly important to keep 
them free of moisture, pitch, oil, fuel mix, 
grease or resin in order for you to 
maintain a firm grip and properly control 
your chain saw .
WARNING
Be sure that the guide bar and saw chain 
are clear of you and all other 
obstructions and objects, including the 
ground. If the upper quadrant of the tip of 
the bar touches any object, it may cause 
kickback to occur (see section on 
reactive forces). Never attempt to start 
the chain saw when the guide bar is in a 
cut or kerf.
For specific starting instructions, see the 
appropriate section of your instruction 
manual.
Starting
WARNING
To reduce the risk of fire and burn 
injuries, start the engine at least 10 feet 
(3 m) from the fueling spot, outdoors 
only.
Start and operate your chain saw 
without assistance. For specific starting 
instructions, see the appropriate section 
of the instruction manual. Proper starting 
methods reduce the risk of injury.
WARNING
To reduce the risk of injury from saw 
chain contact and / or reactive forces, 
the chain brake must be engaged when 
starting the chain saw. If your chain saw 
is equipped with the Quickstop Plus 
chain brake system, it is not sufficient to engage that brake only for starting, 
because the saw chain may begin to 
rotate at high speed when the throttle 
trigger lockout is depressed (releasing 
the brake) in order to blip the throttle 
trigger after starting.
WARNING
Do not drop start. This method is very 
dangerous because you may lose 
control of the chain saw.
There are two recommended methods 
for starting your chain saw.
With the first recommended method, the 
chain saw is started on the ground. 
Make sure the chain brake is engaged 
(see "Chain Brake" chapter in your 
instruction manual) and place the chain 
saw on firm ground or other solid surface 
in an open area. Maintain good balance 
and secure footing.
Grip the front handlebar of the saw firmly 
with your left hand and press down. For 
saws with a rear handle level with the 
ground, put the toe of your right foot into 
the rear handle and press down. With 
your right hand pull out the starter grip 
slowly until you feel a definite resistance 
and then give it a brisk, strong pull.
001BA113 KN