A 4-cycle weed eater usually requires unleaded gas with low ethanol content and a mid-grade minimum octane rating. Using gas with high ethanol content can damage the engine of the equipment and strip off the manufacturer’s warranty on the parts.
Trust us- a 4-cycle weed eater is one of the most useful power equipment that helps you keep your lawn healthy throughout the year.
This particular variant is becoming increasingly popular because of its high-power operation and ease of maintenance. Hence, people don’t mind extending their budget a little to get the best one home.
But before buying one, you should know about the type of gas that powers this equipment so that you don’t end up choosing the wrong fuel.
How Is A 4-Cycle Weed Eater Different From A 2-Cycle One?
Before we tell you about the fuel requirements of a 4-cycle weed eater, let us very briefly state the difference between two-cycle engines and their four-cycle counterparts.
As you may already know, two-cycle engines run on a mix of fuel (or gas) and oil. While the fuel helps the machine generate the required power to function, the oil is used for lubricating the engine components for a smooth operation. However, this doesn’t mean that you can add any amount of fuel and oil to a two-cycle engine.
All 2-cycle weed eater manufacturers specify the correct ratio of gas to oil, so check the operator’s manual to ensure you are using the right amounts of both elements. Some common ratios include 50:1 and 40:1, which are required by weed eaters of top brands like Toro, Troy-Bilt, and Yard-Man, among others.
You can definitely purchase the fuel and oil separately and mix them in the required ratio before adding them to the engine. However, an easier way out is to purchase premixed fuel, which, as the name suggests, comes in a ready-to-use form.
What Kind Of Gas Does A 4-Cycle Weed Eater Use?
The most important feature that distinguishes 2-cycle from 4-cycle engines is the presence of separate gas and oil chambers.
This makes them compatible with almost any regular unleaded gasoline, but most brands recommend using unleaded gasoline that has a maximum ethanol content of not more than 10%. Likewise, it should have a minimum octane rating of 89. This is primarily because too much ethanol will invariably clog the fuel lines and the carburetor, requiring you to replace them frequently.
Keep in mind that you should never mix gas and oil for a four-cycle weed eater. Most importantly, always avoid any gasoline with an ethanol content of more than 10%, like E10 or the ones above it (E15, E83, etc.). Almost all small engines cannot handle the types as they cause irreparable damage to the engine of the equipment, which generally renders the brand warranty invalid.
But how much gas does a weed eater use per hour? The answer to this will largely depend on the power of the engine, the number of parts in the machine, and the duration of the trimming sessions. For example, commercial trimmers use an average of ¼ gallon of oil and gas mixture per hour.
And before we forget- there’s one exception to the separate oil and gas tank rule- the Stihl 4-MIX weed eater. In fact, all four-cycle engines of the Stihl brand are designed to run on a fuel mixture of gas and oil. Under no conditions should you run straight gas through these engines.
Why Is Ethanol Harmful For The Engine?
If you have ever glanced at the cap of the fuel tank of a 4-cycle weed eater, you will see that it reads “ethanol 10% fuel.” This is the case with most four-cycle trimmers. But why should you be wary of ethanol?
Well, the numero uno reason for this is its tendency to draw excess moisture. The engines of most outdoor power equipment aren’t made to handle high amounts of moisture.
In case you didn’t know, the fuel tanks on these engines are vented, which allows outside air (and the moisture in it) to enter the engine. However, under normal circumstances, this amount is usually pretty low to cause any damage.
But if the air has excess humidity and you use a fuel with high ethanol content, it will absorb more moisture, which will eventually deposit at the bottom of the fuel tank as water.
As the fuel tank starts burning the content at the bottom, your weed eater will burn water instead of fuel, causing significant damage to the engine. Moreover, being a solvent, ethanol in unregulated amounts can make the debris inside the fuel tank come loose. It will then float in the fuel and make its way to the entire fuel system, causing massive clogs.
If you’ve ever tried refilling a weed trimmer at a gas station, you would know how difficult it is to find gasoline with 10% or less ethanol. This is especially true for first-timers who may not be well-acquainted with the fuel specifications. That’s why it’s important to check the manufacturer’s recommendations so that you don’t use the wrong fuel.
A better option would be to opt for ethanol-free fuel to do away with the hassle of checking or determining the ethanol content. However, such fuels come with steep price tags, so they may not suit every budget.
An important thing to note is gasoline tends to deteriorate if not stored properly for a long period, so you can add a few drops of a quality fuel stabilizer to the engine.
Choosing The Right Engine Oil For Your 4-Cycle Weed Eater
Your weed eater requires engine oil (irrespective of the type of engine in it) to keep the different parts of the engine lubricated. However, you should be careful while choosing it, as low-quality oil can cause problems with the engine startup, eventually damaging it.
In hindsight, it may lead to unnecessary friction, making the engine work harder to produce the required power. You may also notice the engine getting too hot if you use the wrong oil, like motor or boat oil.
One common mistake to avoid in this regard is using engine oils meant for two-stroke engines in your four-stroke engine weed eater. Similarly, using too much or too little oil can cause problems with the operation, so make sure you refer to the user manual to identify how much oil is needed for the machine.
Furthermore, the viscosity (or thickness) of the oil may need to be changed with a change in temperature.
How To Store Your Four-Cycle Weed Eater?
As we’ve mentioned before, gasoline can deteriorate and even expire over time, so removing it from the fuel tank before storing your weed eater for the season is crucial.
The first step in this simple process is cleaning the trimmer head and the rest of the exterior surfaces to eliminate any debris. Then, open the gas cap and add a small amount of stabilizer to run it through the engine. If you see that the existing gas contains dirt, empty the tank completely and use some fresh gas.
Close the gas cap and turn on the engine for 8 to 12 minutes to allow the stabilizer to spread across the fuel system. Turn off the engine and wait for it to cool down before removing the fuel. This will also allow the stabilizer to dissolve any leftover ethanol inside the engine.
Depending on the model, your weed eater may have a drain plug to help empty the fuel bowl. If not, you need to dismantle it manually, dispose of the fuel, and put it back following the instructions manual.
Finally, store the machine in a cool and dry place till the next season.