MS 194 T
English
25
Retensioning during cutting work:
N Switch off the engine.
N Loosen the nut.
N Hold the bar nose up.
N Use a screwdriver to turn the 
tensioning screw (1) clockwise until 
the chain fits snugly against the 
underside of the bar.
N While still holding the bar nose up, 
tighten down the nut firmly.
N Go to "Checking Chain Tension".
A new chain has to be retensioned more 
often than one that has been in use for 
some time.
N Check chain tension frequently – 
see chapter on "Operating 
Instructions".
N Shut off the engine.
N Wear work gloves to protect your 
hands.
N The chain must fit snugly against 
the underside of the bar and it must 
still be possible to pull the chain 
along the bar by hand when the 
chain brake is released.
N If necessary, retension the chain.
A new chain has to be retensioned more 
often than one that has been in use for 
some time.
N Check chain tension frequently – 
see chapter on "Operating 
Instructions".
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.
NOTICE
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!
NOTICE
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.
Tensioning the Saw Chain 
(side chain tensioner)
Checking Chain Tension
Fuel