How to Adjust A Carburetor On A Weed Eater

You can’t escape it…

If you own a gas-powered tool – you ARE going to have to – eventually – adjust your weed eater carburetor.  This is especially the case with those power tools that take an oil to gas mixture.

It’s not a matter of the quality of the engine – it’s more a matter of time.   Luckily for you, it’s an easy adjustment.   It won’t take more than a few minutes of your time, and some tools you likely have lying around in your garage.

Tools Needed For A Weedeater Carburetor Adjustment

• Phillips-head screwdriver
• Clean workspace
• A string trimmer with gasoline in the tank

How To Adjust A Weedwacker Carb

Step 1: Identify where the carburetor is on your weed eater. It’s usually easy to find because of the fuel bulb that’s attached to it – you use this bulb for priming. It’s likely close to the air filter as well.

Step 2: Once you locate the carb, look on the side. There will be two fuel adjustment screws. They should be labeled “High” and “Low”. They work in tandem – the “High” adjustment screw manages the fuel into the engine at full throttle, while the “Low” adjustment screw regulates how much gasoline flows at idle.

Step 3: Start your weed eater. It needs to be warmed up for the weed eater carb adjustments you are going to perform to be correct. The trimmer head shouldn’t be spinning.

Step 4: Once the gas 2-cycle engine has been running for a few minutes, you can begin adjusting the carburetor by turning screws. We will begin with the “Lo” screw to adjust the engine at idle.

If your engine is idling rough, you will need to adjust the carb by turning the screw counterclockwise until it runs smoothly. If your Weed Eater head is running at idle – FIRST TURN IT OFF – and then adjust the screw by turning it counter-clockwise a turn.

Step 5: We will next adjust the “Hi” screw. Safely position the string trimmer so it doesn’t face anyone, and lock the throttle at full. If the engine is sputtering or rough, adjust the screw clockwise 1/4 at a time until it smooths out. Unlock the throttle.

Step 6: You are now finished!

Step 7: Troubleshooting: If your weed eater is still acting weird, you may have to check the “freshness” of your gas. Bad gas will make your engine run poorly regardless of your carb adjustment.

This may be the case if you kept the gas over the winter – or if water worked in from the atmosphere. The solution is pretty easy – just run all the gas out of the tank, get new fuel, and refill. If it runs better, that was the culprit.

Bonus Tip

Check that the fuel tank has enough fuel. However, do not overfill it. Just make sure the fuel does not go over the line.