HT 105, HT 134, HT 135
English
30
N Use resistor type spark plugs with a 
properly tightened adapter nut.
Installing the Spark Plug
N Screw the spark plug (3) into the 
cylinder. 
N Tighten down the spark plug (3) with 
the combination wrench.
N Press the boot (2) firmly onto the 
spark plug.
N Fit the cover (1) and screw it down 
firmly.
For periods of 3 months or longer
N Drain and clean the fuel tank in a 
well ventilated area.
N Dispose of fuel properly in 
accordance with local 
environmental requirements.
N Run the engine until the carburetor 
is dry – this helps prevent the 
carburetor diaphragms sticking 
together.
N Remove the saw chain and guide 
bar, clean them and spray with 
corrosion inhibiting oil.
N Thoroughly clean the machine – pay 
special attention to the cylinder fins 
and air filter.
N If you use a biological chain and bar 
lubricant, e.g. STIHL BioPlus, 
completely fill the chain oil tank.
N Store the machine in a dry, high or 
locked location, out of the reach of 
children and other unauthorized 
persons.
N Remove chain sprocket cover, saw 
chain and guide bar
Replace the chain sprocket
– replace after using two saw chains 
or sooner
– if the wear marks (a) are deeper 
than 0.02 in (0.5 mm) since this 
would reduce the service life of the 
saw chain. Use a gauge (special 
accessory) to check the depth of the 
wear marks
Using two saw chains in alternation 
helps preserve the chain sprocket.
STIHL recommends the use of original 
STIHL chain sprockets.
Storing the Machine Checking and Replacing the 
Chain Sprocket