Stihl manufactures hedge trimmers in compact models and pole models with blades mounted on long shafts. Pole models contain transmission systems which connect the cutting blades to the hand-held motor. Both types start in the same way with only slight differences in controls. Details do change slightly from model to model, so consult the owner's manual for information specific to your machine.
Mix 2 1/2 fluid ounces of two-cycle engine oil with one gallon of 89 octane unleaded gasoline. Use only fresh gasoline. Stihl recommends Stihl two-cycle oil but equivalent brands work. Fill the hedge trimmer fuel tank and replace the cap. Tighten the cap snugly. Finger tight is good enough.
Remove the plastic sheath from the trimmer blade and set the machine on the ground. When starting the machine keep the engine upright. Do not place a foot on the shaft of a pole trimmer.
Raise the blade lock lever to the lock position. Find this lever at the rear of compact trimmer throttle handles. Pole trimmers do not have the same feature--blade movement depends on engine speed.
Set the throttle of Stihl compact trimmers by squeezing the throttle trigger closed and sliding the throttle lock switch forward. Find this switch on the top of the handle forward of the trigger. Release the throttle trigger and the slide should hold it fully open. Squeeze the throttle trigger of Stihl pole trimmers and slide the throttle lock on the top of the grip back to Start. Release the trigger and it holds the setting.
Find the choke lever on the top left of the motor above the carburetor housing. Controls vary--the choke may be a lever or a knob and pointer. Set the choke to the closed position. Stihl marks the closed settings with a vertical line with horizontal lines above and below.
Find the primer bulb, which is a rubber bulb located near the choke on the top of the carburetor. Press the primer bulb no fewer than five times. Resistance increases when fuel begins flowing. Pumping too much gas through the system floods the carburetor. Stop priming after five pumps and try starting the trimmer.
Hold the trimmer down with the left hand and grasp the handle of the starter cord with the right. Pull slowly until you feel resistance, then pull with short fast strokes. Do not use the full length of the starter rope. Repeat until the engine fires, usually no more than five good pulls.
Move the choke control to full open position as soon as the engine fires. Stihl marks fully open with a symbol like three parallel lines.
Depress the throttle trigger on compact trimmers as soon as the engine runs. This releases the throttle lock and reduces engine speed to an idle. Squeezing and releasing the throttle trigger on pole trimmers allows the trigger lock to shift to the Run position automatically.