How to Adjust the Carburetor on a Stihl HS-80

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Keep the blades and air filter clean for optimal performance.

The Stihl HS-80 hedge trimmer makes quick work of trimming hedges and shrubs around your property. The Stihl HS-80 is a professional series gas-powered hedge trimmer. Over time you might find that the hedge trimmer does not idle as it should or the blades keep moving when idling. When this happens it is necessary to adjust the carburetor on the Stihl HS-80. Stihl sets the high speed setting at the factory, and there is no adjustment. However, it is possible to set the idle speed and adjust the low speed settings to operate the Stihl HS-80 as efficiently as possible.

Step 1

Start the engine and allow it to warm up for five minutes. While the engine is warming up, find the low speed and idle speed adjustment screws. The low speed screw has an "L" stamp, and the idle speed screw has an "LA" stamp next to it. The screws are near the choke lever.

Step 2

Rotate the low speed screw clockwise with a flat screwdriver until it seats fully. Do not force it to turn once it stops. Turn the low speed screw one complete revolution counterclockwise.

Step 3

Turn the idle speed screw clockwise until the cutting blades on the Stihl HS-80 begin to move if the engine stalls while idling. Once the blades start moving, turn the screw 1/2 turn counterclockwise.

Step 4

Rotate the idle speed screw counterclockwise if the blades move while the engine is idling. Once the blades stop moving, turn the idle screw 1/2 turn clockwise.


Kenneth Crawford

Kenneth Crawford is a freelance writer with more than 10 years of experience. His work has appeared in both print and online publications, including "The American Chronicle." Crawford holds an associate degree in business administration from Commonwealth College.