How to use a Weed Wacker Properly – Quick Guide

Keeping the grass short and neat in your property depends as much on the quality of your string trimmer as on your skill to operate it. In this article, I show you how to use a weed wacker effectively for best results.

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A weed wacker or weed eater is a great yard tool for cutting grass and weeds. It is also good for trimming the edges of your lawn. You can also use it to trim vegetation on rocky grounds, around trees, and near the fence where it is implausible to deploy a lawnmower. Weed eaters use a string to cut which makes them more versatile than a lawnmower in difficult and rugged situations.

However, for you to benefit from your weed wacker, you need to know how to use it properly. In this post, I show you how to start and operate all weed eaters including the battery powered, gas-powered, and electric string trimmers. They all use the same principle to cut.

Operating a weed wacker/eater – Step by Step

You obviously need a weed eater with enough gas or a fully charged battery. If you are going to use an electric weed eater, you need a sufficiently long electric cord and of course electricity on the wall outlet. The spool should also be fully loaded. If you need to load a new trimmer line, check out how to restring a weed eater here.

Step 1: Wear protective gear

A string trimmer exposes you to many hazards. So you should wear the following safety equipment and garments to protect yourself.

  • Eye goggles – to protect your eyes from flying debris slung by the trimmer line.
  • Hearing protection equipment – protects you from the noisy motor or 2 stroke engine of a gas trimmer especially if you are using a gas string trimmer
  • Closed-toe shoes – protect your toes from the impact of stones and material being pelted around while the head spins.
  • Gas mask – protects against gas fumes produced by a gas weed wacker and the dust and debris produced when cutting vegetation.
  • Safety gloves – protect your hands from developing blisters and from being hurt in case of an accident.

Step 2: Power up the weed eater.

If you are using a battery weed eater, grab the battery off the charger and click it into place. Ensure that the battery is fully charged to get a decent amount of runtime before the next recharge.

Pro tip: It is good to have at least two batteries so that you can alternate them to complete the yard work in one day.

If you are using a corded weed eater, plug the cord onto the wall outlet.

For a gas weed eater, put the appropriate oil and gas mixture into the tank and be ready to work. The right gas to oil mixture ratio for a 2 stroke weed eater is 40 parts gas to 1 part oil. The gas should be 87 octane with 10% alcohol concentration at most.

Pro tip: 2 cycle engines are sensitive to the fuel/oil mixture. So, don’t put the wrong mixture or you will ruin them before time. Also, be sure to use fresh oil. So, it is best to not premix fuel and oil if you will not use all of it.

Step 3: Check the size of the string

Just to be sure, check that you have a sufficient trimmer line to get the job done. If the string is too short, advance it to the right length using the string dispense mechanism of your weed eater model. If your tool does not have enough cutting string, feed a new spool. Consult your tool’s manual on how to do it or use any of these three ways of putting a string in a weed eater. One of them should work.

Step 4: Start the weed eater

Starting a corded or cordless weed eater is as simple as pressing a start button or flipping the switch to the ON position. But starting a 2 stroke weed eater requires much more than that. Here is how to do it.

How to start a gas weed eater

  1. Put the ON/OFF switch to the ON position.
  2. Prime the trimmer by pressing the primmer button a couple of times until you see some gas through the bubble. Priming pumps some fuel to the carburetor so that the engine can start. You need to prime the engine if you have not started it for some time.
  3. Turn the choke lever to the START or Cold Start position.
  4. Hold the trimmer in place firmly. I prefer to place it on the ground.
  5. Grip the handle of the starter rope in one hand while you put the other on the throttle.
  6. Pull the starter rope a couple of times to start the engine and press the throttle lightly to prevent the engine from dying.
  7. Push the choke lever to the run position and now the engine should run without pressing the throttle trigger. Pro t

Pro tip: If your weedeater won’t start, try putting the choke in the start position, pull the starter cord about 5 times, then put the choke in the middle position and pull the starter rope again until the engine begins to run. Give it some gas and now turn the choke lever to the run position. This should solve the “won’t start problem” of a 2 cycle engine that has not been started for a long time.

If your gas weed wacker is running, then it is ready to cut.

Step 5: Set the operating speed

If your weed whacker has more than one-speed setting, select the appropriate speed. Normally, the type of weed or grass you are cutting determines the speed to set on your tool.

If you are cutting overgrown grass and hardy weeds, the highest speed setting is appropriate. Otherwise, an average speed setting will suffice.

Step 6: Start trimming grass and weeds

Pull the trigger to increase torque and release it to stop the motor from running. Be sure to move the weed wacker in a side-to-side motion for the best results. Keep the head flat to cut evenly without digging into the ground.

Step 7: Bump the head to dispense more cutting string

If the line stops cutting, bump the head slightly onto the ground to dispense more string. However, this only applies to string timmers with the bump to feed mechanism. If your weed eater is automatic, it will release more string as you cut. If the string is depleted, restring the spool.

Step 8: Clean the trimmer after work

Once done trimming, remove the battery and wash the head of the string trimmer with water and then blow the motor with a blower to remove debris. For weedeaters with the motor in the head, be careful not to soak in water.

Step 9: Store the weed eater safely

Store the unit safely in the tool storage room or workshop. Don’t leave it outside.


Hey there! I am an field electrical engineer by day, a blogger by night, and DIYer on weekends. Throughout my career, I have used many tools and learned that getting the right tool for the job is the first step to getting the job done right. This is why I write about tools and tests/reviews them on this blog.