Stihl Fs 80 R Owners Manual

30 English / USAFS 80, FS 80 R, FS 85, FS 85 R
STIHL AutoCut
:
Hold the rotating mowing head 
above the ground – tap it on the 
ground once – about  1 1/4 (3 cm)  
fresh line is advanced. 
The blade on the deflector trims 
overlong line to the correct length – 
avoid tapping head more than once at a 
time.
Line feed operates only if  both lines 
still have a minimum length of  1 
(2.5 cm) .
All other mowing heads
Refer to the instructions supplied with 
the mowing head. To reduce the risk of injury,...

31
FS 80, FS 80 R, FS 85, FS 85 R English / USA
: Place the cutting tool  (6) on the 
thrust plate  (7).
Collar  (see arrows)  must locate in  
cutting tool’s mounting hole.
: Slip thrust washer  (8) and rider 
plate  (9) over the output shaft  (10).
: Block the output shaft and
: Screw the mounting nut  (11) with 
the combination wrench  (12) onto 
the output shaft counterclockwise 
and tighten down firmly.
If the mounting nut is too loose, 
fit a new one.
Removing cutting tool
: Block the output...

32 English / USAFS 80, FS 80 R, FS 85, FS 85 R
Fuel mix ages
Only mix sufficient fuel for a few days 
work, not to exceed 3 months of storage. 
Store in approved fuel-canisters only. 
When mixing, pour oil into the canister 
first, and then add gasoline. Close the 
canister and shake it vigorously by hand 
to ensure proper mixing of the oil with 
the fuel.       
Dispose of empty mixing-oil canisters 
only at authorized disposal locations.
Before fueling, clean the filler cap and 
the area around it to...

33
FS 80, FS 80 R, FS 85, FS 85 R English / USA
The type and style of harness depend on 
the market.
Shoulder Strap
: Put on the shoulder strap ( 1). 
: Adjust the length of the strap so that 
the spring hook ( 2) is about a hand’s 
width below your right hip. 
: Balance the brushcutter.
The use of the harness is described in 
chapter “Approved Combinations of 
Cutting Tool, Deflector, Handle and 
Harness”.
Full harness
: Put on the full harness  (1).
: Adjust length until the spring hook 
(2) is about...

34 English / USAFS 80, FS 80 R, FS 85, FS 85 R
:
Loosen the screw ( 3).
Balancing the Machine
The machine has to be balanced to suit 
the cutting tool you are using.
Carry out the following steps to reach 
the condition described under “Point of 
balance”:
: Slide the clamp up or down the drive 
tube. Tighten the screw moderately. 
Let go of the machine and check to 
see how it is balanced. Point of balance
A Mowing tools
Mowing heads, grass cutting blades 
and brush knife should just touch 
the...

35
FS 80, FS 80 R, FS 85, FS 85 R English / USA
Controls
Control handle on bike handle
Throttle trigger interlock (
1)
Throttle trigger ( 2) 
Slide control ( 3) Control handle on drive tube
Throttle trigger interlock (
1)
Throttle trigger ( 2) 
Slide control ( 3)
Positions of slide control
STOP -O  (4) – engine off – the ignition is 
switched off
#  – normal run position ( 5) – the engine 
is running or can start
START  (6 ) - the ignition is switched on, 
the engine can start Symbol on slide control
h...

36 English / USAFS 80, FS 80 R, FS 85, FS 85 R
:
Set the choke knob ( 8):
For cold start to      
g
For warm start to     e 
– also use this position if engine has 
been running but is still cold
: Press fuel pump bulb ( 9) at least five 
times – even if the bulb is already 
filled with fuel. :
Place the unit on the ground: It must 
rest securely on the engine support 
and deflector. 
Check that the cutting tool is not 
touching the ground or any other 
obstacles.
: Make sure you have a firm footing.
:...

37
FS 80, FS 80 R, FS 85, FS 85 R English / USA
When the engine begins to fire:
: Turn choke knob to  e
and continue cranking.
When the engine begins to fire:
: Blip the throttle trigger immediately 
so that the slide control moves to 
the normal run position  # and the 
engine settles down to idle speed.
Make sure the carburetor is 
correctly adjusted – the cutting tool 
must not rotate when the engine is 
idling.
Your machine is now ready for 
operation.
Stopping the engine
: Push the slide control in...

38 English / USAFS 80, FS 80 R, FS 85, FS 85 R
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...

39
FS 80, FS 80 R, FS 85, FS 85 R English / USA
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.
The carburetor comes from the factory 
with a standard setting.
This setting provides an optimum fuel-air 
mixture under most operating 
conditions.
With this carburetor it is only possible to 
adjust the engine idle speed within fine 
limits.!...