Tensioning The Chain; Checking Chain Tension; Fuel - Stihl MS 661 Instruction Manual

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Tensioning the Chain

1
Retensioning during cutting work:
Shut off the engine.
N
Loosen the nuts.
N
Hold the bar nose up.
N
Use a screwdriver to turn the
N
tensioning screw (1) clockwise until
the chain fits snugly against the
underside of the bar.
While still holding the bar nose up,
N
tighten down the nuts firmly.
Go to "Checking Chain Tension".
N
A new chain has to be retensioned more
often than one that has been in use for
some time.
Check chain tension frequently –
N
see chapter on "Operating
Instructions".
20

Checking Chain Tension

Shut off the engine.
N
Wear work gloves to protect your
N
hands.
The chain must fit snugly against
N
the underside of the bar and it must
still be possible to pull the chain
along the bar by hand.
If necessary, retension the chain.
N
A new chain has to be retensioned more
often than one that has been in use for
some time.
Check chain tension frequently –
N
see chapter on "Operating
Instructions".

Fuel

The engine requires a mixture of
gasoline and engine oil.
WARNING
Avoid direct skin contact with and
breathing in of gasoline fumes.
STIHL MotoMix
STIHL recommends using STIHL
MotoMix. This pre-blended fuel is free of
benzene and lead, stands out because
of a high octane rating, and always
provides the proper mixing ratio.
STIHL MotoMix is blended with STIHL
HP Ultra two-stroke engine oil for
maximum engine life.
MotoMix is not available in all markets.
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 poor quality gasoline or
engine oil is used.
Gasoline
Use only high-quality gasoline with an
octane rating of at least 90 ROC –
leaded or unleaded.
MS 661