Stihl Fs 55 R Instruction Manual

							FS 55, FS 55 C, FS 55 R, FS 55 RCEnglish
9 Important Adjustments
If you cannot set the correct idle speed, 
have your STIHL dealer check your 
power tool and make proper 
adjustments and repairs.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.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!
Your power tool is a one-person 
machine. Do not allow other persons in 
the general work area, even when 
starting.
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.
Warning!
To reduce the risk of personal injury 
from loss of control or contact with the 
running cutting attachment, do not use 
your unit with incorrect idle adjustment. 
At correct idle speed, the cutting attach-
ment should not move. For directions on 
how to adjust idle speed, see the appro-
priate section of your instruction 
manual.
Warning!
Never attempt to operate 
your power tool with one 
hand. Loss of control of 
the power tool resulting in 
serious or fatal injury may 
result. To reduce the risk 
of cut injuries, keep hands and feet 
away from the cutting attachment. 
Never touch a moving cutting attach-
ment with your hand or any other part of 
your body.
002BA055 KN
002BA054 KN
Warning!
Do not overreach. Keep proper footing 
and balance at all times. Special care 
must be taken in slippery conditions 
(wet ground, snow) and in difficult, over-
grown terrain. Watch for hidden 
obstacles such as tree stumps, roots 
and ditches to avoid stumbling. For bet-
ter footing, clear away scrub and 
cuttings. Be extremely cautious when 
working on slopes or uneven ground.
Warning!
To reduce the risk of injury from loss of 
control, never work on a ladder or on 
any other insecure support. Never hold 
the cutting attachment above waist 
height. 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RC English
10Operating Instructions
In the event of an emergency, shut off 
the engine immediately – move the slide 
control / stop switch to 0 or STOP.To reduce the risk of eye and other injury 
always wear proper eye protection (see 
the chapter on Proper Clothing) and 
ensure that bystanders are at least 
50 feet (15 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. Stop the 
engine immediately if you are 
approached. Warning!
As soon as the engine is 
running, this product gen-
erates toxic exhaust 
fumes containing chemi-
cals, such as unburned 
hydrocarbons (including 
benzene) and carbon monoxide, that 
are known to cause respiratory prob-
lems, cancer, birth defects, or other 
reproductive harm. Some of the gases 
(e.g. carbon monoxide) may be color-
less and odorless. To reduce the risk of 
serious or fatal injury / illness from inhal-
ing toxic fumes, never run the machine 
indoors or in poorly ventilated locations.
Warning!
If the vegetation being cut or the sur-
rounding ground is coated with a 
chemical substance (such as an active 
pesticide or herbicide), read and follow 
the instructions and warnings that 
accompanied the substance at issue.
Warning!
Inhalation of certain dusts, especially 
organic dusts such as mold or pollen, 
can cause susceptible persons to have 
an allergic or asthmatic reaction. Sub-
stantial or repeated inhalation of dust 
and other airborne contaminants, in par-
ticular those with a smaller particle size, 
may cause respiratory or other ill-
nesses. Control dust at the source 
where possible. Use good work prac-
tices, 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 recom-
mendations of EPA / OSHA / NIOSH 
and occupational and trade associa-
tions with respect to dust (particulate 
matter). When the inhalation of dust 
cannot be substantially controlled, i.e., 
kept at or near the ambient (back-
ground) level, the operator and any 
bystanders should wear a respirator 
approved by NIOSH / MSHA for the type 
of dust encountered.
Warning!
Do not operate your power tool using 
the starting throttle lock, as you do not 
have control of the engine speed.Warning!
The cutting attachment 
continues to rotate for a 
short period after the 
throttle trigger is released 
(flywheel effect).
Warning!
The rotating cutting attachment may 
fling foreign objects directly or by rico-
chet a great distance.
Warning!
Before you start work, 
examine the area for 
stones, glass, fence wire, 
metal, trash or other solid 
objects. The cutting 
attachment could throw 
objects of this kind.
15m (50ft) 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RCEnglish
11 Warning!
This trimmer / brushcutter is normally to 
be used at ground level with the cutting 
attachment parallel to the ground. Use 
of a trimmer / brushcutter above ground 
level or with the cutting attachment per-
pendicular to the ground may increase 
the risk of injury, since the cutting 
attachment is more fully exposed and 
the power tool may be more difficult to 
control.
Warning!
During cutting, check the tightness and 
the condition of the cutting attachment 
at regular short intervals with the engine 
and attachment stopped. If the behavior 
of the attachment changes during use, 
stop the engine immediately, wait until 
the cutting attachment stops, and check 
the nut securing the attachment for 
tightness and the blade or head for 
cracks, wear and damage.
Warning!
A loose blade or head may vibrate, 
crack, break or come off the trimmer / 
brushcutter, which may result in serious 
or fatal injury. Make sure that the cutting 
attachment is properly tightened. Use 
the wrench supplied or one of sufficient 
length to obtain the proper torque. If the 
blade or head loosens after being prop-
erly tightened, stop work immediately. 
The retaining nut may be worn or dam-
aged and should be replaced. If the 
blade or head continues to loosen, see 
your STIHL dealer. Never use a trimmer 
/ brushcutter with a loose cutting 
attachment.
Warning!
Replace a cracked, damaged or worn-
out head or a cracked, bent, warped, 
damaged, dull or worn out blade imme-
diately, even if damage is limited to 
superficial cracks. Such attachments 
may shatter at high speed and cause 
serious or fatal injury.
Warning!
When using rigid blades, avoid cutting 
close to fences, sides of buildings, tree 
trunks, stones or other such objects that 
could cause the power tool to kick out or 
could cause damage to the blade. 
STIHL recommends use of the nylon 
line heads for such jobs. In addition, be 
alert to an increased possibility of rico-
chets in such situations.
Warning!
If the head, blade or deflector becomes 
clogged or stuck, always shut off the 
engine and make sure the cutting 
attachment has stopped before clean-
ing. Grass, weeds, etc. should be 
cleaned off the blade or from around the 
head at regular intervals.
Warning!
To reduce the risk of unintentional rota-
tion of the cutting attachment and injury, 
always shut off the engine and remove 
the spark plug boot before replacing the 
cutting attachment. To reduce the risk of 
injury, always shut off the engine before 
adjusting the length of the nylon line on 
manually adjustable mowing heads.Warning!
The gearbox becomes hot during oper-
ation. To reduce the risk of burn injury, 
do not touch the gear housing when it is 
hot.
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 
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. 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RC English
12 Catalytic Converter
Your catalytic converter is furnished with 
screens designed to reduce the risk of 
fire from the emission of hot particles. 
Due to the heat from the catalytic 
reaction, these screens will normally stay clean and need no service or 
maintenance. If you experience loss of 
performance and you suspect a clogged 
screen, have your muffler maintained by 
a STIHL servicing dealer.
USING THE CUTTING ATTACHMENT
For an illustration of the various cutting 
attachments and instructions on proper 
mounting see the chapter on Mounting 
the Cutting Attachment in your 
instruction manual.
Using the Mowing Heads
Do not use with mowing line longer than 
the intended length. With a properly 
mounted deflector, the built-in line-
limiting blade will automatically adjust 
the line to its proper length.
Using the unit with an overly long nylon 
cutting line increases the load on the 
engine and reduces its operating speed. 
This causes the clutch to slip 
continuously and results in overheating 
and damage to important components 
(e.g. clutch, polymer housing 
components). Such damage could, 
among other things, cause the cutting 
attachment to rotate at idle.Mowing heads are to be used only on 
trimmer / brushcutters equipped with a 
line-limiting blade in the deflector in 
order to keep the line at the proper 
length (see Main Parts chapter in your 
instruction manual).
If the lawn edges are planted with trees 
or bordered by a fence etc., it is best to 
use a nylon line head. It achieves a 
softer cut with less risk of damaging 
tree bark etc. than polymer blades.
However, the polymer-bladed STIHL 
PolyCut produces a better cut if there 
are no plants along the edge of the lawn. 
Sharpening is not necessary, and worn 
polymer blades are easily replaced. Warning!
Some STIHL power tools 
are equipped with a cata-
lytic converter, which is 
designed to reduce the 
exhaust emissions of the 
engine by a chemical 
process in the muffler. Due to this proc-
ess, the muffler does not cool down as 
rapidly as conventional mufflers when 
the engine returns to idle or is shut off. 
To reduce the risk of fire and burn inju-
ries, the following specific safety 
precautions must be observed.
Warning!
Since a muffler with a catalytic converter 
cools down less rapidly than conven-
tional mufflers, always set your power 
tool down in the upright position and 
never locate it where the muffler is near 
dry brush, grass, wood chips or other 
combustible materials while it is still hot.
Warning!
An improperly mounted or damaged cyl-
inder housing or a damaged / deformed 
muffler shell may interfere with the cool-
ing process of the catalytic converter. 
To reduce the risk of fire or burn injury, 
do not continue work with a damaged or 
improperly mounted cylinder housing or 
a damaged / deformed muffler shell.      
        
          
            
Warning!
To reduce the risk of severe or fatal 
injury from blade contact and / or loss of 
control, never attempt to use a metal 
blade on an FS model for which it is not 
authorized.
000BA015 KN 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RCEnglish
13 STIHL SuperCut mowing head
Fresh line is advanced automatically. 
Frayed line is replaced by a simple 
adjustment (see instruction sheet 
supplied with mowing head).
STIHL AutoCut mowing head
Nylon cutting line advances 
automatically when tapped against the 
ground (TapAction).
STIHL TrimCut mowing head 
Frayed line is replaced by a simple 
adjustment (see instruction sheet 
supplied with mowing head).
STIHL PolyCut mowing head
Uses either nylon lines or nonrigid, 
pivoting polymer blades.STIHL FixCut mowing head
Uses pre-cut lengths of nylon line.
Observe wear indicators.
Do not continue using the mowing head 
if the raised moldings (1) on the base 
are missing or worn – see right 
illustration above. The mowing head may otherwise shatter and flying objects 
could result in injury to the operator or 
bystanders. Install a new mowing head.
Risk of Kickout (Blade Thrust) with 
All Rigid Cutting Blades
This kickout (blade thrust) may cause 
loss of control of the power tool and may 
result in serious or fatal injury to the 
operator or bystanders. To reduce the 
risk of injury, extreme caution should be 
used when cutting with the shaded area 
of any rigid blade. Warning!
To reduce the risk of serious injury, 
never use wire or metal-reinforced line 
or other material in place of the nylon 
cutting lines. Pieces of wire could break 
off and be thrown at high speed toward 
the operator or bystanders.
002BA177 KN
Warning!
Three rectangular wear limit marks are 
applied to the base (periphery) of the 
PolyCut. To reduce the risk of serious 
injury from breakage of the head or 
blades, the PolyCut must not be used 
when it has worn as far as one of these 
marks. It is important to follow the main-
tenance instructions supplied with the 
head.
Warning!
If the wear limit marks are ignored, there 
is a risk of the cutting attachment shat-
tering and flying parts injuring the 
operator or bystanders. To reduce the 
risk of accidents from shattered blades, 
avoid contact with stones, metal and 
similar solid objects. Check PolyCut 
blades for cracks at regular intervals. If 
a crack is found on one blade, always 
replace all blades.
Warning!
Kickout (blade thrust) is the sudden and 
uncontrolled motion towards the opera-
tors right or rear that can occur when 
the shaded area (especially the darkly 
shaded area) of a rotating blade comes 
in contact with a solid rigid object like a 
tree, rock, bush or wall. The rapid coun-
terclockwise rotation of the blade may 
be stopped or slowed, and the cutting 
attachment may be thrown to the right or 
to the rear.
002BA135 KN 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RC English
14 Using the Grass Cutting Blade
All kinds of grass and weeds can be 
easily cut with the grass cutting blade. 
The power tool is swept in an arc similar 
to a scythe.
The 4-tooth grass cutting blade is 
intended to cut grass and weeds. It has 
4 cutting knives with cutting edges on 
both sides, i.e. front and rear. When the 
cutting edges on one side become dull, 
the blade can be turned over to utilize 
the cutting edges on the other side.
The 8-tooth grass cutting blade is 
recommended for cutting fern or reed.Both types of grass cutting blade have to 
be resharpened when all cutting edges 
are dull.
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.
Strictly follow the maintenance and 
repair instructions in the appropriate 
sections of your instruction manual.
Wear gloves when handling or 
performing maintenance on blades. Warning!
To reduce the risk of serious or fatal 
injury from blade breakage, never 
attempt to use this blade to cut woody 
materials.
000BA020 KNWarning!
Use only identical STIHL replacement 
parts for maintenance and repair. Use of 
non-STIHL parts may cause serious or 
fatal injury.
Warning!
Always stop the engine and make sure 
that the cutting attachment 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 instruction man-
ual. Have such work performed by your 
STIHL servicing dealer only.
Warning!
Use the specified spark plug, and make 
sure it and the ignition lead are always 
clean and in good condition. Always 
press the spark plug boot snugly onto 
the spark plug terminal of the proper 
size. (Note: If the terminal has a detach-
able SAE adapter nut, it must be 
securely attached.) A loose connection 
between the spark plug 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 
spark plug 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 modi-
fied. 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.
Warning!
Never repair damaged cutting attach-
ments by welding, straightening or 
modifying the shape. This may cause 
parts of the cutting attachment to come 
off and result in serious or fatal injuries. 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RCEnglish
15 Keep blades sharp. 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.
Before storing for longer than a few 
days, always empty the fuel tank. See 
chapter Storing the Machine in the 
instruction manual. 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RC English
16
Approved Combinations
Select correct combination from the 
table according to the cutting 
attachment you intend to use.Cutting attachments
Mowing heads
1STIHL SuperCut 20-2
2STIHL AutoCut C 25--2
3STIHL AutoCut 25-2
4STIHL TrimCut 31-2
5STIHL FixCut 25-2
Approved Combinations of Cutting Attachment, Deflector, Handle and Harness
Cutting attachment Deflector Handle Harness
12
34
56
78
9
10
11
12
13
1415
16
1415
16
1819
1918
1719
681BA128 KN
For safety reasons only the 
cutting attachments, deflectors, 
handles and shoulder straps 
shown in each row of the table 
may be used together. No other 
combinations are permitted 
because of the risk of accidents. 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RCEnglish
17 6STIHL PolyCut 20-3
Metal mowing attachments
7Grass cutting blade 230-4
8Grass cutting blade 230-8
Deflectors
9Deflectoronly for mowing heads
10Deflector with
11Skirt and blade for all mowing heads 
12Deflector without skirt and blade for 
all metal mowing attachments
Handles
13Loop handle
14Loop handlewith
15Barrier bar
16Bike handle
Harnesses
17Shoulder strap may be used
18Shoulder strap must be used
19Full harness may be used
Equipment
Among other parts, the complete unit in 
includes:
–Cutting attachment
–Deflector
–Handle
–Harness (only with bike handle)
Mounting the handlebar
NPlace the clamp (1) and handle 
support (2) against the drive 
tube (3).
NFit the handlebar (4) in the handle 
support – the rubber handle (5) 
must be on the left (viewed from the 
engine).
NPlace the clamp (6) on the handle 
support.
NInsert the screws (7) through the 
holes in the parts and screw them 
into the clamp (6) as far as stop.
Non-metal grass cutting blades 
are not approved.Warning!
Based on the cutting attachment being 
used:
Choose the proper deflector in order to 
reduce the risk of injury from thrown 
objects and contact with the cutting 
attachment.
Make sure your unit is equipped with the 
proper handle and harness in order to 
reduce the risk of injury from loss of con-
trol and contact with the cutting 
attachment: use grass cutting metal 
blades on this unit only if equipped with 
a bike handle or a loop handle with bar-
rier bar.
Do not use rigid plastic blades, brush 
knifes or circular saw blades on this unit.
Mounting the Bike Handle
13 25
7
6
4
233BA025 KN 
						

							FS 55, FS 55 C, FS 55 R, FS 55 RC English
18 NMount the handlebar (4) on the 
drive tube (3) about  6 in (15 cm) (A) 
forward of the engine housing.
NLine up the handlebar and tighten 
down the screws firmly.
Mounting the control handle
NUse the combination wrench or 
screwdriver to take out the screw (8) 
– the nut (9) remains in the control 
handle (10).
NPush the control handle onto the 
handlebar (4) until the holes (12) 
line up – the throttle trigger (11) 
must point towards the gearbox.
NInsert the screw (8) and tighten it 
down firmly.
Fitting the throttle cableNPush the throttle cable (13) into the 
retainer (14).
4
A
3
233BA018 KN
Do not kink the throttle cable or 
lay it in tight radii – make sure the 
throttle trigger moves freely.
002BA357 KN
128
9
4
11
12
10
14
1314 13
233BA027 KN