How does a gasoline brush cutter work?

The brush cutter is a very useful gadget for keeping your garden in order and is easy to use once you get the hang of it. Today I will teach you that trick.

I gave my brother a brush cutter for his birthday. A few days later he called me to ask me for advice because he did not know how to use it or what gasoline it required, so I went and did the tutorial.

gasoline brush cutter

As he learned quickly and ended up happy with his brush cutter, I decided to make this practical guide for use, with tips and useful information for you to master too.

If you want to know how I chose the ideal brush cutter for my brother, I leave you this complete buying guide with the best brush cutters for sale.

How a gasoline brush cutter works

I make this guide to gasoline cutters without neglecting the electric version, but since these are easier to use than the first ones, I will focus on the fuel ones.


These devices are composed of an engine that is usually at the opposite end of the cutting head, a tube that connects both parts, one or 2 handles to maneuver and accelerate, the fuel tank under the engine, an air filter and a carrying strap that is optional, but I recommend it.


The first thing to understand is that there are brush cutters with 2 and 4-stroke gasoline engines. You do not have to know the whole theory; the important thing is that you know that 2-stroke engines work with a mixture of fuel and oil in the 98/02 ratio. This mixture is made to keep the engine lubricated.

The 4 stroke engines have a separate compartment for oil, so its fuel is placed without mixing. Brush cutters with a 2-stroke engine are more common, but as a general rule the number of strokes is mentioned in the brush cutter’s name.

The 2-stroke brush cutters produce more smoke than the 4-stroke ones, because the first one burns gasoline and oil at the same time, resulting in a greater amount of smoke. In return, it is a more powerful engine that will help you cut the grass even faster.


You can buy the gasoline and oil separately to prepare the mixture yourself or buy the product already mixed and ready to use. For every liter of gasoline you must use 20ml of oil. For each gallon are 100ml.

You must buy brush cutter engine oil, thus extending the useful life of your product. For gasoline there is no problem since anyone works, regardless of its octane rating.

After mixing, use a funnel and/or filter to avoid particulates in the fuel tank.

Mix the gasoline that you are going to use within a maximum of 1 month. If you can mix the one that you will use at the moment, better, because the product is gradually damaged by joining it with the oil.

Gasoline Primer

This is a small clear rubber bubble that comes in various brush cutter models; it is used as part of the cold start.

By pressing it several times, it sucks a little gasoline into it to help start the engine.

If you are going to start a brush cutter that has been off for a few minutes, you do not need to press the primer because hot start is more straightforward.

Air Filter

It guarantees pure air to the engine and must be cleaned from time to time, because it fills with all kinds of particles. Many times they have a switch that plays a role in in turning on the brush cutter.

The filter can allow or prevent the flow of air with the provided switch. Flow is impeded as a step to cold start the brush cutter.

Cutter Head

In the head you can find cutting discs, a blade or the cutting wire, that depends on the model or the type of work you need to do. To prune the garden, the cutting wire is enough.

If you have a multi-function brush cutter, surely you have about 4 or 5 more options for the head, such as saws or extension tubes.

Ignition and Acceleration

Every mower includes a power button that must be pressed first before attempting to start, as this allows current to flow throughout the appliance.

Turning it off cuts off the power and the engine won’t start (as if you removed the battery from a vehicle)

If your brush cutter won’t start, check the button’s condition – the starter rope is that piece that is pulled to start the brush cutter. It is usually in the engine area.

Then there’s acceleration, which is done with a trigger, lever, or button on the handles or in an area of the engine on some models. A button is included to maintain the same speed that as pressing it you can stop pressing the accelerator.

The maximum speed of the brush cutters depends on the model and its power, which is measured in DC.

  • For a garden with not very stubborn grass, a brush cutter of up to 36 cc does the job.
  • If you have a farm or a very large piece of land that you need to prune, use models of more than 45 cc.

Accessories and Protection

The more powerful or larger you want your brush cutter, the more weight it will have.

That is why they sell a harness that is placed like a backpack and is hooked to the machine. This distributes the weight to the back, hips, and shoulders.

Protection for the face and eyes is essential because stones or part of the brush can jump and injure you.

A clear plastic visor or protective glasses work well.

Another important factor is that brush cutters generate a lot of noise, above the level bearable for humans.

At first you will not notice anything, but with constant use of the mower you will begin to have hearing problems. The use of protective helmets or headphones is recommended to avoid damaging your eardrums.

gasoline brush cutter works

How do I turn on the brush cutter?

Since you know all the terms, I can explain how to use the gasoline brush cutter.

  1. Verify that it has gasoline and that the head has its cutting tool.
  2. Before starting the brush cutter make sure you have the necessary protection. Covering your eyes and face is vital because a stone or patch of grass can pop off you and hurt you.
  3. You can also wear ear protection. If you are going to use your brush cutter on a regular basis, ear protection is essential to avoid damage to your eardrums due to the high decibels of the machine.
  4. Make sure the power button is allowing power to flow.
  5. Press the gas primer several times until you see it fill with fuel. This step is only necessary if you are going to start the cold brush cutter.
  6. The air flow must be blocked to start the ignition, so check on the filter that the button or lever indicates that it is closed.
  7. Grab the starter rope and pull hard until you hear it make an attempt to start. At that moment you stop and open the air flow.
  8. Pull the lighter again and get ready, so you get to start the cold brush cutter. If you are using it and need to turn it off for a few minutes, the ignition is much more direct: just make sure the power button is in the on position and pull the cord.

Ready, with that you can start using the brush cutter. It is recommended not to mow the lawn so often.

Tips for using the brush cutter

You already have your brush cutter on, but do you know how to use it? It’s a simple machine and it gets the job done pretty quickly, but I’ll give you a couple of tips to help you become an expert in no time:

  • Always use the same speed: accelerate to a certain point and use the hold throttle button that is usually near the trigger to accelerate. This makes the entire lawn look mowed with the same machine and gives you a smooth finish.
  • For better mowing, go from the lowest grass to the highest. This helps you keep an overview of what you have already worked on and prevents ups and downs in the garden.
  • Move the running brush cutter away from any hard surface such as trees or ground, as this could break the cutting wire.
  • Never leave gasoline in the fuel tank. If you’ve finished using the brush cutter and it will be off for more than 6 hours, drain all the fuel. Once it’s empty, turn it on to finish burning any remaining residue. This way you ensure that the carburetor does not get damaged and you extend the life of your mower.
  • Some large bushes can be very tough on brush cutter thread. In those cases try to use cutting discs or saws.

Frequent doubts about brush cutters

While I was selecting the brush cutter that I gave my brother I read several questions and doubts about the brush cutter, so I selected the most common ones to answer them here:

Which one better: electric brush cutter or a gasoline brush cutter?

This depends on the taste of each one. The gasoline ones are more powerful and with freedom of movement, but the electric ones are cheaper and less noisy.

  • If you have a small garden or patio with a nearby outlet, an electric outlet is a good idea.
  • If you have a larger space and need to move or turn, the gasoline is for you.

How to improve the life of the brush cutter threads?

Avoid hitting hard surfaces or trees with your cutting lines. Cutting the garden lawn in an exclusive way is enough to extend its useful life.

How to change the filter of a brush cutter?

Every brush cutter is different so there are a large number of filters.

To make sure you get the correct one, you need to remove it from its compartment. In the instruction manual it should say how to do it, but in general the filter has a lid that pops up.

Once the filter is out, you can clean and maintain it or take it with you to the store to get one just like that.

How to change the brush cutter thread?

Here it also depends a bit on the model, but they all follow the same principle: you must uncover the head to remove the previous thread or place the thread for the first time.

How can I repair a gasoline brush cutter?

If your brush cutter has a problem, it is always preferable to take it to a professional, especially if you do not have knowledge of engines.

That’s all you need to know to have your gasoline brush cutter working with you.

It is a very useful tool that with regular maintenance can last a long time.