Fuel - Stihl FS 85 Instruction Manual

English
WARNING
If the mounting nut has become too loose, fit a
new one.
NOTICE
Remove the tool used to block the shaft.
10.9 Removing the Metal Cutting
Attachment
WARNING
Wear protective gloves to reduce the risk of
direct contact with the sharp cutting edges.
► Block the shaft.
► Unscrew the mounting nut clockwise.
► Remove cutting attachment and its mounting
hardware from the gearbox – but do not
remove the thrust plate (9).

11 Fuel

The engine requires a mixture of gasoline and
engine oil.
WARNING
Avoid direct skin contact with fuel and breathing
in of gasoline fumes.
11.1 STIHL MotoMix
STIHL recommends using STIHL MotoMix. This
pre-blended fuel is free of benzene and lead, is
distinguished by a high octane rating, and
always provides the proper mixing ratio.
STIHL MotoMix uses STIHL HP Ultra two-stroke
engine oil for optimum engine life.
MotoMix is not available in all markets.
11.2 Mixing fuel
NOTICE
Unsuitable fuels or a mixing ratio that deviates
from the specification can lead to severe engine
damage. The engine, seals, fuel lines and fuel
tank may be damaged if low-quality gasoline or
engine oil is used.
11.2.1 Gasoline
Use only high-quality gasoline with an octane rat‐
ing of at least 90 ROC – leaded or unleaded.
72
Gasoline with an alcohol component exceeding
10% can cause impaired engine performance in
engines with manually adjustable carburetors
and thus should not be used in these engines.
Engines with M-Tronic deliver full engine per‐
formance using gasoline with an alcohol compo‐
nent of up to 27% (E27).
11.2.2 Engine oil
If you mix the fuel yourself, use only STIHL two-
stroke engine oil or another high-performance
engine oil classified as JASO FB, JASO FC,
JASO FD, ISO-L-EGB, ISO-L-EGC or ISO-L-
EGD.
STIHL specifies STIHL HP Ultra two-stroke
engine oil or an equivalent high-performance
engine oil in order to maintain emission limits
over the machine's service life.
11.2.3 Mixing ratio
with STIHL two-stroke engine oil 1:50; 1:50 =
1 part oil + 50 parts gasoline
11.2.4 Examples
Quantity of gaso‐ STIHL two-stroke
line engine oil 1:50
Liters Liters
1 0.02
5 0.10
10 0.20
15 0.30
20 0.40
25 0.50
► Pour oil into an approved safety fuel canister
first, then add gasoline and mix thoroughly
11.3 Storing fuel mixture
Store in approved safety fuel canisters only in a
dry, cool and secure place protected against light
and sunlight.
Fuel mixture deteriorates with age – mix only as
much as needed for a few weeks. Do not store
fuel mixture for longer than 30 days. The fuel
mixture can become unusable more quickly if
exposed to light, sunlight or low or high tempera‐
tures.
STIHL MotoMix however can be stored for up to
5 years without any problems.
► Shake the canister containing the fuel mixture
thoroughly before refueling
11 Fuel
(ml)
(20)
(100)
(200)
(300)
(400)
(500)
0458-393-8721-C