4
3
2
b
a
Place the cutting attachment (1) in
N
position.
WARNING
Collar (a) must locate in the cutting
attachment's mounting hole (b).
Securing the cutting attachment
Fit the thrust washer (2) – convex
N
side must face up.
Fit the rider plate (3).
N
A rider plate (3) for sawing applications
is available as a special accessory. It
allows the full depth of cut of the saw
blade to be used.
Block the shaft.
N
Fit the nut (4) counterclockwise and
N
tighten it down firmly.
FS 311
WARNING
If the mounting nut has become too
loose, fit a new one.
NOTICE
1
Remove the tool used to block the shaft.
Removing the cutting attachment
Block the shaft.
N
Unscrew the mounting nut
N
clockwise.
Pull the cutting attachment with its
N
mounting hardware off the gearbox.
Fuel
This engine is certified to operate on
unleaded gasoline and the STIHL two-
stroke engine oil at a mix ratio of 50:1.
Your engine requires a mixture of high-
quality 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 an octane rating below 89 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 damage the
engine. For this reason STIHL
recommends that you use only quality
unleaded gasoline!
Gasoline with an ethanol content of
more than 10% can cause running
problems and major damage in engines
and should not be used.
For further details, see
www.STIHLusa.com/ethanol
The ethanol content in gasoline affects
engine speed – it may be necessary to
readjust the carburetor if you use fuels
with various ethanol contents.
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