Stihl Fs 90 R Manual

FS 90, FS 90 R
English
39 For periods of about 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, clean and inspect the 
cutting attachment. Coat metal 
cutting attachments with corrosion 
inhibitor.
NThoroughly clean the machine – pay 
special attention to the cylinder fins...

FS 90, FS 90 R
English
40
Placing power tool on the ground
NShut off the engine.
NLay your power tool on its back so 
that the cutting attachment 
mounting face is pointing up.
Replacing Nylon Line
Always check the mowing head for signs 
of wear before replacing the nylon line.
WARNING
If there are signs of serious wear, 
replace the complete mowing head.
The nylon mowing line is referred to as 
"nylon line" or "line" in the following.
The mowing head is supplied with 
illustrated...

FS 90, FS 90 R
English
41 The mowing head is supplied with 
illustrated instructions for replacing the 
blades. Keep the instructions for the 
mowing head in a safe place.
WARNING
To reduce the risk of injury, always shut 
off the engine before installing the 
blades.
NRemove the mowing head.
NReplace blades as shown in the 
illustrated instructions.
NMount the mowing head on the 
machine.
Maintenance Work
STIHL recommends that you have 
servicing and repair work carried out 
exclusively by an authorized...

FS 90, FS 90 R
English
42
Maintenance and Care
The following intervals apply to normal operating conditions only. If your daily work-
ing time is longer or operating conditions are difficult (very dusty work area, etc.), 
shorten the specified intervals accordingly.
before starting work
after finishing work or daily
after each refueling stop
weekly
monthly
every 12 months
if problem
if damaged
as required
Complete machineVisual inspection (condition, leaks)XX
CleanX
Replace any damaged partsXX
Control...

FS 90, FS 90 R
English
43
Spark arresting screen in mufflerCheckXX
Clean or replaceXX
All accessible screws and nuts (not adjust-
ing screws)RetightenX
Anti-vibration elements (rubber buffers, 
springs)CheckXXX
Have replaced by servicing dealer
1)X
Cutting attachmentVisual inspectionXX
ReplaceX
Check tightnessXX
Metal cutting attachment SharpenXX
Gearbox lubricationCheckX
ReplenishX
Safety labels ReplaceX
1)STIHL recommends an authorized STIHL servicing dealer.2)Remove shroud - see "Spark Arresting...

FS 90, FS 90 R
English
441Fuel Filler Cap
2Carburetor Adjusting Screws
3Starter Grip
4Spark Plug Boot
5Muffler with Spark Arresting Screen
6Bike Handle
7Throttle Trigger
8Slide Control
9Throttle Trigger Lockout
10Throttle Cable Retainer
11Carrying Ring
12Manual Fuel Pump
13Choke Knob
14Air Filter Cover
15Fuel Tank
16Machine Support
17Handle Support
18Wing Screw
19Loop Handle
20Barrier Bar
#Serial Number
Main Parts
418
#
13
7
981120
19
8
79
6
17
101110
15
16
14
5
1
2
12
3
249BA069 KN 

FS 90, FS 90 R
English
45
Definitions
1 Fuel Filler Cap
For closing the fuel tank.
2 Carburetor Adjusting Screws
For tuning the carburetor.
3 Starter Grip
The grip of the pull starter, for 
starting the engine.
4 Spark Plug Boot
Connects the spark plug with the 
ignition lead.
5 Muffler with Spark Arresting Screen
Muffler reduces engine exhaust 
noise and diverts exhaust gases 
away from operator.
Spark arresting screen is designed 
to reduce the risk of fire.
6 Bike Handle
For easy control of the...

FS 90, FS 90 R
English
46
Definitions
1 Mowing Head
The cutting attachment, i. e. 
mowing head, for different 
purposes.
2 Deflector for Mowing Heads
The deflector is designed to reduce 
the risk of injury from foreign objects 
flung backwards toward the 
operator by the cutting attachment 
and from contact with the cutting 
attachment.
3 Line Limiting blade
Metal blade at the deflector in order 
to keep the line of the mowing head 
at the proper length.
4 Deflector with Skirt for all Mowing...

FS 90, FS 90 R
English
47
Ignition System
Electronic magneto ignition
Fuel System
All position diaphragm carburetor with 
integral fuel pump
Weight
Overall length
FeaturesUsers of this unit should carry out only 
the maintenance operations described 
in this manual. STIHL recommends that 
other repair work be performed only by 
authorized STIHL servicing dealers.
Warranty claims following repairs can be 
accepted only if the repair has been 
performed by an authorized STIHL 
servicing dealer using...

FS 90, FS 90 R
English
48 Observe all country-specific waste 
disposal rules and regulations.
STIHL products must not be thrown in 
the garbage can. Take the product, 
accessories and packaging to an 
approved disposal site for environment-
friendly recycling.
Contact your STIHL servicing dealer for 
the latest information on waste disposal.
Not for California
Your Warranty Rights and Obligations
The U.S. Environmental Protection 
Agency (EPA) and STIHL Incorporated 
are pleased to explain the Emission...