How to Adjust the Carburetor on a Troy-Bilt Weed Trimmer

Troy-Bilt produces weed trimmers that require little upkeep, except the usual routine maintenance items that should be addressed periodically depending on the number of hours service since the last maintenance was performed. If your machine seems to be stopping or stalling out more frequently than usual and you have adhered to the basic schedule of routine maintenance, it's likely that the carburetor is out of adjustment and needs a bit of attention.

Three screwdrivers
credit: Hemera Technologies/ Images

Step 1

Clean the air filter before adjusting the carburetor so that you are sure you are receiving the proper air flow before altering the carburetor settings. Open the air filter cover located on the left side of the engine by depressing the small plastic tab inward with your fingers. Pull the right side of the cover outward toward you, and allow it to swing to the left.

Step 2

Remove the gas cap if you have difficulty removing the air filter cover. On some models, the gas cap impedes the motion of the cover as it is removed. Once the air filter cover is off, pull the air filter straight out. The filter is beneath the air filter cover, and is not attached to anything.

Step 3

Clean the air filter in warm water, using mild dish soap. Allow it to dry, then reinstall it by following the reverse of the removal steps.

Step 4

Start the weed trimmer and allow it to warm up to normal operating temperature. Let the engine idle, then take a long, slender slotted screwdriver and insert it into the idle adjustment screw hole on the top of the engine housing. Turn the screw clockwise to increase the engine idle revolutions per minute and counterclockwise to decrease the RPMs.

Step 5

Set an idle speed that allows the engine to run without laboring when the engine is at idle. The engine is idling too fast if the head of the weed trimmer rotates while the engine is idling.