STIHL MM 55 Owner's Manual
STIHL MM 55
Warning!
Read and follow all safety
precautions in Instruction Manual –
improper use can cause serious or
fatal injury.
Advertencia!
Lea y siga todas las precauciones
de seguridad dadas en el manual
de instrucciones – el uso incorrecto
puede causar lesiones graves o
mortales.
{
Instruction Manual
Manual de instrucciones
Instruction Manual
1 - 28
Manual de instrucciones
29 - 60
Contents
English
MultiSystem 2
Guide to Using this Manual 2
Safety Precautions and Working
Techniques 3
Approved MultiTools 10
Adjusting the bicycle handle 10
Fuel 11
Fueling 12
Original Instruction ManualPrinted on chlorine-free paper
Starting / Stopping the Engine 12
Extra weight 14
Wheels 15
Operating Instructions 16
Replacing the Air Filter 17
Engine Management 17
Adjusting the Carburetor 18
Spark Plug 19
Engine Running Behavior 20
Rewind Starter 20
Storing the Machine 21
Inspections and Maintenance by
Dealer 21
Maintenance and Care 22
Printing inks contain vegetable oils, paper can be recycled.
Main Parts 23
Specifications 24
Special Accessories 25
Maintenance and Repairs 25
STIHL Incorporated Federal
Emission Control Warranty
Statement 26
Trademarks 28
Allow only persons who fully understand
the manuals of the MultiEngine and the
MultiTool to operate your power tool.
To receive maximum performance and
satisfaction from your STIHL power tool,
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 power tool. 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 the
two manuals.
Warning!
Because this MultiEngine is the engine
for a high-speed power tool, some special safety precautions must be
observed to reduce the risk of personal
injury. Careless or improper use may
cause serious or even fatal injury.
Make sure your unit is equipped with the
proper deflector for the type of cutting
attachment being used. Always wear
proper eye protection.
{
© ANDREAS STIHL AG & Co. KG, 2011
0458-469-8621-B. M9-5.H11.CP.
0000000537_004_GB
MM 55, MM 55 C
1
English
469BA028 KN
+
+
MultiSystem
In the STIHL MultiSystem, various
MultiEngines and MultiTools are
combined to form a machine. In this
Instruction Manual, the functional unit of
MultiEngine and MultiTool is referred to
as a machine.
Accordingly, the instruction manuals for
the MultiEngine and the MultiTool
constitute the entire Instruction Manual
for the machine.
Always read both manuals carefully
before using your machine for the first
time and keep them safe for future
reference.
Guide to Using this Manual
Pictograms
All the pictograms attached to or
embossed on the machine are shown
and explained in this manual.
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:
N A 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:
N Loosen the screw (1).
N Lever (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 an imminent risk of severe or
fatal injury.
Warning!
Indicates a hazardous situation which, if
not avoided, could result in severe or
fatal injury.
Caution!
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 differ from those
described in this manual, please contact
your STIHL dealer for assistance.
2
MM 55, MM 55 C
English
Safety Precautions and
Working Techniques
Because this MultiEngine
is the engine for a highspeed 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 manuals and
the safety precautions of
your MultiEngine and
MultiTool periodically.
Careless or improper use
may cause serious or
fatal injury.
Have your STIHL dealer show you how
to operate your power tool. Observe all
applicable local safety regulations,
standards and ordinances.
Warning!
Do not lend or rent your power tool without the instruction manuals. Be sure that
anyone using it understands the information contained in these manuals.
Use your power tool only for the
applications described in the instruction
manual of the MultiTool you are using.
Warning!
Do not use it for other purposes, since
misuse may result in personal injury or
property damage, including damage to
the machine.
Warning!
Minors should never be allowed to use
this power tool. Bystanders, especially
children, and animals should not be
allowed in the area where it is in use.
Warning!
To reduce the risk of injury to bystanders and damage to property, never let
your power tool run unattended. When it
is not in use (e.g. during a work break),
shut it off and make sure that unauthorized persons do not use it.
Most of these safety precautions and
warnings apply to the use of all STIHL
power tools. Different models may have
different parts and controls. See the
appropriate section of your MultiEngine
and MultiTool instruction manuals for a
description of the controls and the
function of the parts of your model.
Safe use of a power tool involves
1. the operator
2. the power tool
3. the use of the power tool
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 machine 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 machine.
Warning!
Prolonged use of a power tool (or other
machines) 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
whitefinger 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
MM 55, MM 55 C
3
English
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:
– Wear gloves and keep your hands
warm.
– A power tool with loose components
will tend to have higher vibration
levels.
– 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 tool.
Proper Clothing
Warning!
To reduce the risk of injury, the operator
should wear proper protective apparel.
Warning!
Never operate your
power tool unless wearing goggles or properly
fitted protective glasses
with adequate top and
side protection complying
with ANSI Z 87.1 (or your applicable
national standard). To reduce the risk of
injury to your face STIHL recommends
that you also wear a face shield or face
screen over your goggles or protective
glasses.
Power tool noise may damage your
hearing. Wear sound barriers (ear plugs
or ear mufflers) to protect your hearing.
Continual and regular users should
have their hearing checked regularly.
Be particularly alert and cautious when
wearing hearing protection because
your ability to hear warnings (shouts,
alarms, etc.) is restricted.
Good footing is very
important. Wear sturdy
boots with nonslip soles.
For further instructions on proper
clothing see the safety precautions in
the instruction manual of the MultiTool
you are using.
THE POWER TOOL
For illustrations and definitions of the
power tool parts see the chapter on
"Main Parts."
Warning!
Never modify this power tool in any way.
Only attachments supplied by STIHL or
expressly approved by STIHL for use
with the specific STIHL MultiEngine
model are authorized. Although certain
unauthorized attachments are useable
with STIHL power tools, their use may,
in fact, be extremely dangerous.
If this tool 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 machine if it is damaged.
In case of doubt, have it checked by your
STIHL servicing dealer.
THE USE OF THE POWER TOOL
Transporting the Power Tool
Warning!
Always switch off the engine and make
sure the working tool has stopped
before putting a power tool down. When
transporting your power tool in a vehicle, properly secure it to prevent
turnover, fuel spillage and damage to
the power tool.
Fuel
Your STIHL power tool uses an oil-
gasoline mixture for fuel (see the
chapter on "Fuel" of your instruction
manual).
4
MM 55, MM 55 C
Warning!
001BA220 KN
001BA227 KN
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 power tool. Note that
combustible fuel vapor may escape
from the fuel system.
Fueling Instructions
Warning!
Fuel your power tool 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 power tool carefully so as to
allow any pressure build-up in the tank
to release slowly. 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
machine.
Warning!
Check for fuel leakage
while refueling and during operation. If fuel
leakage is found, do not
start or run the engine
until the leak is fixed and
any spilled fuel has been wiped away.
Take care not to get fuel on your clothing. If this happens, change your
clothing immediately.
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 opening with the raised positioning
marks on the grip of the cap and 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
(approx. 1/4 turn).
English
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 corresponding 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.
Misaligned, damaged or broken cap
N If 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.
Left: Base of cap in closed posi-
tion (with open space)
Right: Base of cap correctly posi-
tioned for installation
MM 55, MM 55 C
5
English
001BA226 KN
N To 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. Then, twist the cap
clockwise, closing it normally.
N If 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.
Screw Cap
Warning!
Unit vibrations can cause
an improperly tightened
fuel filler cap to loosen or
come off and spill quantities of fuel. In order to
reduce the risk of fuel
spillage and fire, tighten the fuel filler
cap by hand as securely as possible.
See also the "Fueling" chapter in your
Instruction Manual for additional
information.
Before Starting
Before starting work, open up the bike
handle and lock it in position with the
rotary knob. See chapter on "Adjusting
the Bike Handle."
Warning!
Always check your power tool for proper
condition and operation before starting,
particularly the throttle trigger, starting
throttle lock, slide control / stop switch,
working tool and deflector. The throttle
trigger must move freely and always
spring back to the idle position. Never
attempt to modify the controls or safety
devices.
Warning!
Never operate your power tool if it is
damaged, improperly adjusted or maintained, or not completely or securely
assembled.
Inspect for loose parts (nuts, screws,
etc.) and for cracked, bent, warped or
damaged working tools.
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.
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 power tool.
Warning!
To reduce the risk of injury from a
MultiTool rotating in the wrong direction,
check that the position of the gearbox is
correct and change it if necessary.
On metal tools (top illustration), position
the gearbox so that the shaft is below
the drive tube.
Use for:
– BF-MM cultivator blades with
pointed tines
– BK-MM cultivator blades with
curved tines
– FC-MM edger
– RL-MM aerator
– MF-MM dethatcher
On sweeping tools (bottom illustration),
position the gearbox so that the shaft is
above the drive tube.
Use for:
– KB-MM bristle brush
– KW-MM STIHL PowerSweep
6
MM 55, MM 55 C
English
469BA027 KN
5m (16ft)
Check the instruction manual for the
MultiTool to ensure you are using the
appropriate deflector for that MultiTool.
Starting
Start the engine at least 10 feet (3 m)
from the fueling spot, outdoors only.
For specific starting instructions, see the
appropriate section of your MultiEngine
and MultiTool manuals.
Place the power tool on firm ground or
other solid surface in an open area.
Maintain good balance and secure
footing.
Warning!
Always stand to one side of the unit to
avoid the risk of injury from contact with
the rotating working tool.
Warning!
To reduce the risk of
injury from loss of control, be absolutely sure
that the working tool is
clear of you and all other
obstructions and
objects, including the ground, because
when the engine starts at starting-throttle, engine speed will be fast enough for
the clutch to engage and move the
working tool.
Once the engine has started,
immediately blip the throttle trigger,
which should release the starting throttle
and allow the engine to slow down to
idle.
Warning!
Your power tool is a one-person
machine. Do not allow other persons in
the general work area, even when
starting.
Stop the engine and working tool
immediately if you are approached.
To reduce the ri sk o f eye and o ther injury
always wear proper eye protection (see
section on "Proper Clothing") and
ensure that bystanders are at least
16 feet (5 m) away. To reduce the risk of
damage to property, also maintain this
distance from such objects as vehicles
or windows. Any coworkers who must be
in the restricted area should also wear
goggles or protective glasses.
Warning!
To reduce the risk of injury from loss of
control, do not attempt to "drop start"
your power tool.
Warning!
When you pull the starter grip, do not
wrap the starter rope around your hand.
Do not let the grip snap back, but guide
the starter rope to rewind it properly.
Failure to follow this procedure may
result in injury to your hand or fingers
and may damage the starter
mechanism.
See also the safety precautions on
Starting in the instruction manual of the
MultiTool.
Important Adjustments
Warning!
To reduce the risk of personal injury
from loss of control or contact with the
running working tool, do not use a
power tool with incorrect idle adjustment. At correct idle speed, the working
tool should not move. For directions on
how to adjust idle speed, see the appropriate section of your instruction
manual.
If you cannot set the correct idle speed,
have your STIHL dealer check your
power tool and make proper
adjustments and repairs.
MM 55, MM 55 C
7
English
469BA045 KN
During Operation
Holding and Controlling the Power Tool
Always hold the unit firmly with both
hands on the handles while you are
working. Wrap your fingers and thumbs
around the handles, keeping the
handles cradled between your thumb
and forefinger. Keep your hands in this
position to have your power tool under
control at all times.
Warning!
To reduce the risk of injury from loss of
control, never work on a ladder or on
any other insecure support.
Working Conditions
Operate and start your power tool only
outdoors in a well ventilated area.
Operate it under good visibility and
daylight conditions only. Work carefully.
Warning!
As soon as the engine is
running, this product generates toxic exhaust
fumes containing chemicals, such as unburned
hydrocarbons (including
benzene) and carbon monoxide, that
are known to cause respiratory problems, cancer, birth defects, or other
reproductive harm. Some of the gases
(e.g. carbon monoxide) may be colorless and odorless. To reduce the risk of
serious or fatal injury / illness from inhaling toxic fumes, never run the machine
indoors or in poorly ventilated locations.
Warning!
Inhalation of certain dusts, especially
organic dusts such as mold or pollen,
can cause susceptible persons to have
an allergic or asthmatic reaction. Substantial or repeated inhalation of dust
and other airborne contaminants, in particular those with a smaller particle size,
may cause respiratory or other illnesses. Control dust at the source
where possible. Use good work practices, such as operating the unit so that
the wind or operating process directs
any dust raised by the power tool away
from the operator. Follow the recommendations of EPA / OSHA / NIOSH
and occupational and trade associations with respect to dust ("particulate
matter"). When the inhalation of dust
cannot be substantially controlled, i.e.,
kept at or near the ambient (background) level, the operator and any
bystanders should wear a respirator
approved by NIOSH / MSHA for the type
of dust encountered.
Operating Instructions
Warning!
Do not operate your power tool using
the starting throttle lock, as you do not
have control of the engine speed.
In the event of an emergency, switch off
the engine immediately – move the slide
control / stop switch to 0 or STOP.
8
MM 55, MM 55 C
Warning!
The muffler and other parts of the
engine (e.g. fins of the cylinder, spark
plug) become hot during operation and
remain hot for a while after stopping the
engine. To reduce risk of burns do not
touch the muffler and other parts while
they are hot.
Warning!
To reduce the risk of fire and burn injury,
keep the area around the muffler clean.
Remove excess lubricant and all debris
such as pine needles, branches or
leaves. Let the engine cool down sitting
in the upright position on concrete,
metal, bare ground or solid wood away
from any combustible substances.
Warning!
Never modify your muffler. The muffler
could be damaged and cause an
increase in heat radiation or sparks,
thereby increasing the risk of fire and
burn injury. You may also permanently
damage the engine. Have your muffler
serviced and repaired by your STIHL
servicing dealer only.
MAINTENANCE, REPAIR AND
STORING
Maintenance, replacement, or repair of
the emission control devices and
systems may be performed by any
nonroad engine repair establishment or
individual. However, if you make a
warranty claim for a component which
has not been serviced or maintained
properly or if nonapproved replacement
parts were used, STIHL may deny
coverage.
Warning!
Use only identical STIHL replacement
parts for maintenance and repair. Use of
non-STIHL parts may cause serious or
fatal injury.
Strictly follow the maintenance and
repair instructions in the appropriate
section of your MultiEngine and
MultiTool instruction manuals. Please
refer to the maintenance charts
respectively the maintenance notes in
these manuals.
Warning!
Always stop the engine and make sure
that the working tool is stopped before
doing any maintenance or repair work or
cleaning the power tool. Do not attempt
any maintenance or repair work not
described in your MultiEngine and
MultiTool instruction manuals. Have
such work performed by your STIHL
servicing dealer only.
Wear gloves when handling or
performing maintenance on any blade.
Warning!
Never repair damaged working tools by
welding, straightening or modifying the
shape. This may cause parts of the
working tool to come off and result in
serious or fatal injuries.
English
Warning!
Use the specified spark plug and make
sure it and the ignition lead are always
clean and in good condition. Always
press spark plug boot snugly onto spark
plug terminal of the proper size. (Note: If
terminal has a detachable SAE adapter
nut, it must be attached.) A loose connection between spark plug boot and
the ignition wire connector in the boot
may create arcing that could ignite combustible fumes and cause a fire.
Warning!
Never test the ignition system with the
ignition wire boot removed from the
spark plug or with a removed spark
plug, since uncontained sparking may
cause a fire.
Warning!
Do not operate your power tool if the
muffler is damaged, missing or modified. An improperly maintained muffler
will increase the risk of fire and hearing
loss. If your muffler was equipped with a
spark-arresting screen to reduce the
risk of fire, never operate your power
tool if the screen is missing or damaged.
Remember that the risk of forest fires is
greater in hot or dry weather.
Tighten all nuts, bolts and screws,
except the carburetor adjustment
screws, after each use.
Do not clean your machine with a
pressure washer. The solid jet of water
may damage parts of the machine.
Store the power tool in a dry and high or
locked location out of reach of children.
MM 55, MM 55 C
9
English
469BA025 KN
BF-MM
BK-MM
RL-MM
FC-MM
KB-MMKW-MM
MF-MM
1
469BA007 KN
Before storing for longer than a few
days, always empty the fuel tank. See
chapter "Storing the Machine" in the
instruction manual.
Approved MultiTools
The following STIHL MultiTools may be
attached to the MultiEngine:
MultiTool Intended use
BF-MM Soil cultivator
BK-MM Bolo tines
RL-MM Lawn aerator
FC-MM Lawn edger
MF-MM Dethatcher
KW-MM STIHL
PowerSweep
KB-MM Bristle brush
TM
Adjusting the bicycle handle
N Loosen knob (1)
N Fold out bicycle handle in working
position as far as it will go
N Tighten knob
10
MM 55, MM 55 C
English
Fuel
This engine is certified to operate on
unleaded gasoline and the STIHL twostroke engine oil at a mix ratio of 50:1.
Your engine requires a mixture of highquality gasoline and two-stroke air
cooled engine oil.
Use mid-grade unleaded gasoline with a
minimum octane rating of 89 (R+M/2)
and no more than 10% ethanol content.
Fuel with a lower octane rating may
increase engine temperatures. This, in
turn, increases the risk of piston seizure
and damage to the engine.
The chemical composition of the fuel is
also important. Some fuel additives not
only detrimentally affect elastomers
(carburetor diaphragms, oil seals, fuel
lines, etc.), but magnesium castings and
catalytic converters as well. This could
cause running problems or even
damage the engine. For this reason
STIHL recommends that you use only
high-quality unleaded gasoline!
Gasoline with an ethanol content of
more than 10% can cause running
problems and major damage in engines
with a manually adjustable carburetor
and should not be used in such engines.
The ethanol content in gasoline affects
engine running speed – it may be
necessary to readjust the carburetor if
you use fuels with various ethanol
contents.
Warning!
To reduce the risk of personal injury
from loss of control and / or contact with
the running cutting tool, do not use your
unit with incorrect idle adjustment. At
correct idle speed, the cutting tool
should not move.
If your power tool shows an incorrect
idle adjustment, have your STIHL dealer
check your power tool and make proper
adjustments and repairs.
The idle speed and maximum speed of
the engine change if you switch from a
fuel with a certain ethanol content to
another fuel with a much higher or lower
ethanol content.
This problem can be avoided by always
using fuel with the same ethanol
content.
Use only STIHL two-stroke engine oil or
equivalent high-quality two-stroke
engine oils that are designed for use
only in air cooled two-cycle engines.
We recommend STIHL HP Ultra 2-Cycle
Engine Oil since it is specially
formulated for use in STIHL engines.
Do not use BIA or TCW rated (twostroke water cooled) mix oils or other
mix oils that state they are for use in both
water cooled and air cooled engines
(e.g., outboard motors, snowmobiles,
chain saws, mopeds, etc.).
Take care when handling gasoline.
Avoid direct contact with the skin and
avoid inhaling fuel vapor. When filling at
the pump, first remove the container
from your vehicle and place the
container on the ground before filling. To
reduce the risk of sparks from static
discharge and resulting fire and/or
explosion, do not fill fuel containers that
are sitting in or on a vehicle or trailer.
The container should be kept tightly
closed in order to limit the amount of
moisture that gets into the mixture.
The machine‘s fuel tank should be
cleaned as necessary.
Fuel mix ages
Only mix sufficient fuel for a few days
work, not to exceed 3 months of storage.
Store in approved fuel-containers only.
When mixing, pour oil into the container
first, and then add gasoline. Close the
container and shake it vigorously by
hand to ensure proper mixing of the oil
with the fuel.
Gasoline
US gal. US fl.oz.
12.6
2 1/2 6.4
5 12.8
Dispose of empty mixing-oil containers
only at authorized disposal locations.
Oil (STIHL 50:1 or equivalent high-quality oils)
MM 55, MM 55 C
11
English
232BA046 KN
1
4
56
7
3
START
2
STOP
002BA036 KN
8
469BA033 KN
9
Fueling
Before fueling, clean the filler cap and
the area around it to ensure that no dirt
falls into the tank.
Always thoroughly shake the mixture in
the canister before fueling your
machine.
In order to reduce the risk of burns or
other personal injury from escaping gas
vapor and fumes, remove the fuel filler
cap carefully so as to allow any pressure
build-up in the tank to release slowly.
After fueling, tighten fuel cap as securely
as possible by hand.
Starting / Stopping the
Engine
Operating elements
1 Throttle trigger lockout
2 Throttle trigger
3 Slide control
Slide control positions
4START – Start – the ignition is
switched on – the engine can be
started
5 Operating position F – Run – engine
is running or can start
6STOP-0 – engine off – ignition is
switched off
Symbol on slide control
7 h – Stop sign and arrow – to switch
off the engine, push the slide control
in the direction of the arrow (h) to
STOP-0
Starting
N Fold out bicycle handle in working
position – see "Adjusting the bicycle
handle"
N Press the throttle trigger lockout and
throttle trigger in succession
N Hold both triggers down
N Move the slide control to START
and hold it in position too
N Release the throttle trigger, slide
control and throttle trigger lockout in
succession = starting throttle
position
12
N Set the choke lever (8)
MM 55, MM 55 C
English
469BA005 KN
469BA004 KN
469BA006 KN
8
469BA034 KN
g if the engine is cold
e If the engine is warm – even if the
engine has already run but is still
cold
N Press the fuel pump bulb (9) at least
5 times - even when bulb is filled
with fuel
Starting
N Fold in wheels, if present
objects – see also
"Starting/stopping the engine" in the
MultTool Instruction Manual
N Assume a steady stance – as
shown; always stand at the side of
the machine – risk of injury by
rotating working tool!
N With the left hand, press the
machine firmly against the ground –
hand on loop handle
Do not stand or kneel on the shaft!
Do not pull out the starter rope
completely – risk of breakage!
Version with Easy2Start
N Pull the starter grip slowly until you
feel it engage and then give it a
slow, even pull
Do not pull out the starter rope
completely – risk of breakage!
Both versions
N Do not let the starter grip snap back
– guide it slowly back into the
housing so that the starter rope can
rewind properly
N continue cranking
When the engine has turned over for the
first time
N Lay the unit on the ground in a
secure position: It must rest on the
flange of the engine and the support
on the frame. The working tool must
not touch the ground or any other
MM 55, MM 55 C
N Grab the starter grip with your right
hand
Version without Easy2Start
N Pull the starter grip slowly until you
feel it engage and then give it a
brisk, strong pull
N at the latest after the fifth time the
starter rope is pulled, move the
choke lever (8) to e
N continue cranking
Once the engine is running
N Blip the throttle trigger so that the
engine settles down to idle speed
13
English
469BA053 KN
1
2
3
4
5
The machine is now ready for use.
If the carburetor has been set correctly,
the working tool should not rotate when
the engine is idling!
Switching off the engine
N Push the slide control in the
direction of the arrow (h) to STOP-0
If the engine does not start
Choke lever
If the choke lever was not returned to e
in time after the engine turned over for
the first time, then the engine has
flooded.
N Set choke lever to e
N Move the throttle trigger, slide
control and throttle trigger lockout to
the starting throttle position
N Start the engine – to do this, pull
starter rope briskly – 10 or 20 pulls
may be needed
N Move the slide control to F
N Set the choke lever to e – even if
the engine is cold
N Restart the engine
Fuel tank run until dry
N After refueling, press the fuel pump
bulb at least five times – even if it is
full of fuel.
N Set the choke lever in accordance
with the engine temperature
N Restart the engine
Extra weight
To increase the weight on the MultiTool,
the MultiEngine can be retrofitted with
an additional weight (special
accessory).
Always use original STIHL additional
weight. Using other weights can lead to
damage to the machine and personal
injuries.
Attaching additional weight
No wheels are attached to the
MultiEngine
Use the combination wrench to loosen
and tighten the weights.
Detach the weights on the side without
the square – to do this:
If the engine still does not start
N Move the slide control to STOP-0
N Remove the spark plug – see
"Spark plug"
N Dry spark plug
N Crank the engine several times with
the starter – to clear the combustion
chamber
N Replace the spark plug – see "Spark
plug"
14
The weights (1) on the side with the
square (2) remain mounted on the bolt.
N Unscrew the hexagon head bolt (3)
and remove the outer weight (4)
N Detach the inner weight (5) and
remove it from the bolt
MM 55, MM 55 C
English
6
469BA054 KN
1
2
3
4
5
3
6
469BA035 KN
2
4
1
7
7
5
3
1
N Push additional weight (1) with bolt
through the hole (6) in the flange; in
the process, rotate it until the
square (2) engages in the opening
in the flange
N Turn the inner weight (5) onto the
bolt and tighten
N Fasten outer weight (4) with the
hexagon head bolt (3) in the thread
of the inner weight and tighten
One or two weights can be mounted on
each side of the additional weight as
needed.
Weights on
each side
14.4lbs. (2kg)
28.8lbs. (4kg)
Additional weight,
total
In this case, have the additional weight
installed by a servicing dealer.
STIHL recommends that maintenance
and repair work be carried out only by
authorized STIHL dealers.
Wheels
For convenient transport, the
MultiEngine can be retrofitted with a set
of wheels (special accessory).
Always use original STIHL wheels.
Using other wheels can lead to damage
to the machine and personal injuries.
Installing wheels
No additional weight is attached to the
MultiEngine
To simplify installation, turn the machine
so that it rests on the handles.
The maximum additional weight is
8.8 lbs. (4 kg). Never use higher
additional weight. This can cause
damage to the machine.
Wheels are attached to the MultiEngine
If wheels (special accessory) – see
"Wheels" – are already attached to the
MultiEngine, then additional parts are
required in order to install the additional
weight.
N Insert the two sleeves (1) in the
frame
N Push the frame onto the flange
MM 55, MM 55 C
15
English
8
469BA036 KN
N Insert the bolt (2) with the
washer (3) through the hole (4) in
the flange
N Fit the washer (3) and tighten it
down with the nut (5)
N Fasten the notched plate (6) to the
frame with the screws (7) in the
threaded holes – in the process,
push the notched plate toward the
handle
N The wheels must fold down
automatically in working position; if
necessary, loosen the nut (5) by a
quarter turn
Additional weight is attached to the
MultiEngine
If additional weight (special accessory) –
see "Additional weight" – is already
attached to the MultiEngine, then
additional parts are required in order to
install wheels.
In this case, have the wheels installed by
a servicing dealer.
STIHL recommends that maintenance
and repair work be carried out only by
authorized STIHL dealers.
N Loosen knob (8)
N Engage knob in the desired working
position and tighten it
Operating Instructions
During 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
unnecessary 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
engine are greater during this period.
The engine develops its maximum
power after about 5 to 15 tank fillings.
During Operation
After a long period of full throttle
operation, allow the engine to run for a
short while at idle speed so that engine
heat can be dissipated by the flow of
cooling air. This protects enginemounted components (ignition,
carburetor) from thermal overload.
After Finishing Work
Folding the wheels in and out
The wheels can be locked in various
positions.
If the wheels are not needed during
work, fold in the wheels.
16
Storing for a short period: Wait for the
engine to cool down. Empty the fuel tank
and keep the machine in a dry place,
well away from sources of ignition, until
you need it again. For longer out-ofservice periods – see "Storing the
Machine".
MM 55, MM 55 C
English
1
469BA037 KN
2
469BA038 KN
3
4
Replacing the Air Filter
If there is a noticeable loss of engine
power
N Set choke lever to g
N Remove screw (1)
N Remove filter cover (2)
N Remove coarse dirt from inside the
filter cover and around the filter
Engine Management
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.
N Remove the air filter (3)
N Check the air filter – replace if
necessary
Replace any damaged parts.
N Insert air filter (3) in the filter
housing (4)
N Refit the filter cover and screw it
down
MM 55, MM 55 C
17
English
Adjusting the Carburetor
The carburetor comes from the factory
with a standard setting.
The carburetor has been adjusted for
optimum performance and fuel
efficiency in all operating states.
The high speed adjusting screw on this
carburetor can only be set within narrow
limits!
Standard position
N Switch off the engine
N Mount MultiTool
N Check the air filter – replace if
necessary
N Have the spark arrestor (present
only in some countries) checked –
see "Inspection and maintenance
by the servicing dealer"
N Turn the high speed screw (H)
counterclockwise as far as possible
– max. 3/4 turn
N Carefully turn the low speed
adjusting screw (L) clockwise until it
is firmly seated, then open it 1 turn
counterclockwise
N Start the engine and let it warm up if
necessary
N Using the idle speed screw (LA), set
the idle speed so that the working
tool does not move
Fine adjustment
A marginal adjustment of the setting of
the high speed adjusting screw (H) may
be necessary if the engine does not run
satisfactorily in mountain country or at
sea level.
Approx. value
Turn the high speed screw (H) approx.
1/4 turn per 1000 m (3300 ft) difference
in elevation.
Adjustment conditions
N Adjust to standard setting
N Let the engine warm up for
approx. 3 min at full throttle
In the mountains
N Turn the high speed screw (H)
clockwise (leaner) – until there is no
longer a noticeable increase in
speed – max. as far as possible
At sea level
N Turn the high speed screw (H)
counterclockwise (richer) – until
there is no longer a noticeable
increase in speed – max. as far as
possible
It is possible that the maximum speed is
already obtained at the standard setting.
Setting the idle speed
Whenever the low speed screw (L) has
been adjusted, it is usually also
necessary to adjust the idle speed
adjusting screw (LA).
N Let the engine warm up for
approx. 3 min
Engine stops when idling
N Slowly turn idle speed screw (LA)
clockwise until the engine runs
smoothly – the working tool must not
move
18
MM 55, MM 55 C
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