0458-759-8221-C
12
English 
5 IMPORTANT SAFETY INSTRUCTIONS
■
■ To return the base of the cap to the proper starting 
position for installation:
– Drop the cap into the fuel tank opening (A).
– Turn the cap counter-clockwise with slight pressure 
until it drops fully into the fuel tank opening 
(approx. 1/4 turn) (B). This will rotate the base of the 
cap into the correct starting position for 
installation (C). The exterior positioning mark (1) on 
the cap will line up with the "unlocked" symbol on the 
fuel tank housing. The interior positioning mark (3) 
should be under the grip and not in line with the outer 
positioning mark (1). 
– Then, turn the cap clockwise, closing it normally.
■ If your fuel cap still does not tighten properly, it may be 
damaged or broken. Stop using the unit and take it to your 
authorized STIHL dealer for repair.
Vapor Lock
WARNING
■ Vapor lock occurs when fuel in the fuel line or carburetor 
vaporizes, causing bubbles to block the free flow of liquid 
fuel into the carburetor.
■ Vapor lock cannot be relieved or affected by opening the 
fuel tank. Removing the fuel filler cap without first allowing 
the chain saw to cool adequately can result in fuel 
spraying. Always follow the instructions in this section 
when removing the fuel cap.
■ To relieve vapor lock:
– Place the Master Control Lever in the start 
position  and try to start the chain saw, @ 14.
– If your chain saw will not restart, or if vapor lock 
occurs again, the chain saw is being used in 
conditions too extreme for the fuel being used. 
Discontinue use and let the engine cool completely 
before attempting to start the chain saw.
– Using good quality, fresh fuel (stored less than 30 
days) also can help reduce the occurrence of vapor 
lock.
5.6 Using the Chain Saw
5.6.1 Before Operation
WARNING
■ Misuse or unauthorized use may result in personal injury 
and property damage.
– Use the chain saw only as described in this 
instruction manual.
■ For proper assembly of the bar and chain:
– Read and follow the instructions on mounting the 
guide bar and chain, @ 10.2.1. 
■ The chain, guide bar and sprocket must match each other 
in gauge and pitch. Before mounting or replacing:
– Read the information on guide bar and chain 
combinations, @ 26.
– Read and follow the instructions on kickback and 
other reactive forces, @ 6.
– Select the shortest bar that will meet your cutting 
needs. Longer bars add weight and may be more 
difficult to control.