The weed eater gas oil mixture is one of the extra steps you have to take when it comes to running a 2-stroke engine. Getting the weed eater mix ratio right can make the difference between a weed eater that will last for years or a weed eater that could seize in just a few minutes.
So, let’s take a closer look at the different factors that will determine what the weed eater fuel mixture should be and what you can do to make sure you avoid any weed eater gas mix ratio problems.
Why the Weed Eater Gas/Oil Mixture is So Important (The Short Explanation)
If you use too little 2-stroke oil in your weed eater fuel mix, the engine will not be provided with sufficient lubrication. This means the inside of the engine will quickly wear down and fail. On the other hand, if you use too much oil in the fuel, your weed eater will struggle to operate and eventually stop working.
How to Figure Out What Weed Eater Fuel Mixture You Need (4 Ways)
Now you know that getting the weed eater gas oil mixture right can make a world of difference and that using too much or too little is a problem. But how do you figure out what your weed eater fuel mixture should actually be? Let’s find out.
Check the Owner’s Manual
The only way to guarantee that you will use the right oil mix is to check the manual that came with your weed eater. All manufacturers specify in their manuals the specific mixture that you should use and provide a ratio of the fuel to oil that is best suited to their engines.
Check the Gas Cap
Depending on your specific weed whacker, you may find that the oil fuel mixture is printed on the machine. In addition, some gas caps have the specific ratio printed on the gas cap for easy reference. So, take a look at your weed eater and check the gas cap to see if the ratio is specified.
Knowing Your Weed Eater Brand
If you take a look at manufacturers such as Echo, Stihl, and Husqvarna, you’ll see that all their modern 2-cycle engines use the same mix ratio. This means you can use the same mix between your weed eater, edgers, chainsaws, hedge trimmer, etc. So, a 50:1 weed eater gas oil mixture is the typical mix you’ll want to use. But again, it’s worth checking the user manual if you are unsure.
Check On the Internet
Now if you are anything like me, I tend not to hold on to a manual for too long, so you may not have the manual on hand. Therefore, if you are still unsure, you can always take a look on the internet. Typically manufacturers provide online versions of all of their manuals for the new and recent models. Also, if you have an old weed eater that is no longer on the manufacturer’s webpage, you may be able to search in Google or on forums.
What Can Happen if You Get Your Weed Eater Mix Ratio Wrong (The Consequences)
Now, there are two ways you can get the wrong mix ratio, either too much or too little oil. So, let’s look at each of the scenarios and see the potential consequences.
Using Too Much 2-Cycle Oil in a String Trimmer
Using too much oil in your weed eater fuel mixture basically means you are reducing the ratio from 50:1 to 45:1, 40:1, etc. As a consequence, these are a few of the effects you’ll encounter.
Smoking Engine
The first thing you will probably notice is your weed eater smoking way more than is normal. This is because the is more oil being burned as the engine combusts. Now you can use a reduced smoke product like the Echo 2-cycle oil, but you’ll still see more smoke than you would if you had the mixture right.
Poor Combustion
Once you add more oil to the mix, your weed whacker will have a harder time vaporizing and igniting the fuel mix in the carburetor/cylinder. This means that you will struggle to keep your weed eater running smoothly. You may find that your weed eater bogs down and possibly stalls, and you may not even be able to get it started.
Carbon Build Up
When any oil burns, it produces carbon. Now, running your weed eater with the correct fuel-to-oil mixture limits the production of carbon, allowing the engine to exhaust most of the carbon through the muffler. But when there is a lot of oil in the mix, your weed eater can’t get rid of the carbon so easily. Therefore, the combustion chamber will become sooted with carbon deposits which will affect the performance of your weed eater. For example, your spark plug will get sooted up with carbon and your weed eater will not produce a spark effectively.
Using Too Little 2-Cycle Oil in a String Trimmer
Now let’s take a look at what could happen to your weed eater if you don’t use enough 2-cycle oil. This would be like using a 55:1, 60:1, or even higher ratio in your weed eater.
Reduced Lubrication
The less oil you mix in your 2-cycle weed eater gas oil mixture, the less lubrication your engine will have. This means your engine will begin to overheat, expand internally, and wear very quickly. You could start to see a reduction in performance, and your weed eater will be on a path to seizing very quickly.
In my experience, the first components affected when not using enough 2-cycle oil in your string trimmer are the piston, piston ring, and cylinder. The overheating expands the metal of the piston ring and piston, which then wears against the cylinder.
So not only will there be a lack of compression and power, but your weed eater will finally seize. This is because the internal parts of the engine expand beyond their limits until they finally fail and seize.
How to Mix Gas and Oil for a Weed Eater (Step By Step)
When it comes to how to mix gas and oil for a weed eater, there are three common methods people tend to use. These three methods range in accuracy, ease, and equipment needed. Therefore, let’s take a closer look at them and see which will suit you best.
Using a Pre-Mix Fuel to Oil Mixture
As its name suggests, a pre-mix is a simple oil and fuel mixture that has been pre-mixed at the factory to precise quantities. For example, Stihl manufactures its “Moto Mix 50:1 Fuel Mixture,” which is ready to go straight out of the container. So, there is no need for additional tools, cans, or measuring.
While you pay a premium for the product, you eliminate any worry about messing up the quantities. So, if you don’t use that much gas when weed-eating, this is a very convenient solution.
Using a Specific Oil Volume Container
Ok, so what does it mean to use specific volume containers? Well, two-cycle oil for weed eaters comes in a variety of different size containers, making mixing simple. For example, if you have a 2.5-gallon gas can, you would need 2.5 gallons of fuel and 6.4 fl oz of oil. Whereas, if you have a 5-gallon gas can, you would need 12.8 fl oz of 2-cycle oil.
To make things easier, companies such as Stihl sell oil in a variety of different size oil containers to match the size of your gas can. So, all you need to do is use the appropriate size oil container to match your gas can, and the ratio is done for you.
Here are a few examples of different-sized oil containers and how much fuel/oil mix they can make.
- 6 fl oz = 1 gallon
- 2 fl oz = 2 gallons
- 4 fl oz = 2.5 gallons
- 8 fl oz = 5 gallons
Measuring Oil by Volume
The downside to using products such as Moto Mix and size-specific oil containers is that they are a bit more expensive. If you use a lot of 2-cycle fuel oil mix, it is more cost-effective to buy the oil in bulk and measure the quantities yourself. So, let’s go over how you can make your own weed eater gas oil mixture using a large container of oil.
How to Mix Gas and Oil for a Weed Eater Yourself (Step By Step)
To get started with mixing your own gas mix, you’ll need to make sure that you have all the right tools and equipment. Here is a quick look at what you will need.
Tools & Equipment to Mix 2-Cycle Oil & Fuel
- Measuring Container
- Fuel-Safe Gas Can
- Marker Pen
Step 1 Determine the Quantities
The first step is to determine how much fuel mix you want to make and then to work out how much oil you will need. You probably already have a gas can you can use to make your mix. The size of your gas can will be the factor that determines how much mix you will be making. So if you have a 2.5-gallon gas can, you will need to use a mix for 2.5 gallons. Typically, you use 2.6 fl oz of oil per 1 gallon, so with a little math, you can work out how much oil you will need in relation to the gas can you are going to use. Also, you will usually find printed on the side of the 2-cycle oil can the mix volumes for a range of different volumes of gasoline.
Step 2 Measure the 2-Cycle Oil
Once you know how much oil you need, you can use a measuring jug or another similar device to measure the 2-cycle oil. Now you may have an oil container with an included measuring device, such as a window in the container with a liquid volume scale, but I’ve never found these to be all that accurate. So, I recommend using a separate measuring cup.
Step 3 Add the Oil to the Gas Can
Next, once you have finished measuring the 2-cycle oil, you’ll want to pour the oil into your gas can. When you do this step, try to pour the oil so it lands directly onto the bottom of the can and doesn’t drip along the sides. This makes mixing a little bit easier.
Step 4 Add the Gas to the Gas Can
Now it’s time to fill your gas can with fresh fuel. So by adding the oil to the gas can first, there is no need to mix the fuel. This is because the movement the fuel makes when added to the gas can does the mixing for you.
Step 5 Label & Store the Mixture
The final step is to label your mixture. This is so you don’t get the gas-only mix you use for your lawn mower mixed up with your 2-cycle mix. Now when I label my gas cans, I just use a marker pen to write ”mix” on the side of the can.
What to Do If You Have Been Using the Wrong Gas/Oil Mix in Your Weed Wacker
If you have been using the wrong mix in your weed eater, all you need to do is swap to the right mix. So, if you still have gas in the gas tank of your weed eater, pour it out and fill it with the right mixed fuel. You should quickly notice a significant improvement when operating your weed eater with the right gas.
However, it is a good idea to check the spark plug for carbon buildup. Now if you have used the wrong mixture for a long time and are concerned that your weed eater has some piston damage, you can remove the muffler and look inside the engine.
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