Mixing Fuel for 2 Stroke Engines
If you use any outdoor power equipment, it’s likely that you will need to use a mixture of fuel and oil. In this article, we’ll walk you through how to determine the proper ratio, and how to mix it. There are several pre-mixed options available to purchase in stores, but if you own your equipment, it will be much cheaper to mix it yourself.
Determining the Correct Ratio
For every two-stroke engine, there’s a proper ratio of fuel to oil that you will need to put into the engine for it to run properly. Make sure that you consult your owner’s manual to determine what the correct ratio is for your equipment. If you don’t have the manual on hand, the ratio is usually printed on the fuel cap. The most common ratios we see are 40:1 or 50:1 – this means 40 (or 50) parts of fuel to 1 part oil.
What You’ll Need
- Large measuring device for fuel
- Smaller measuring device for oil
- Fuel
- Two-stroke engine oil
Determine How Much Fuel
The amount of mixed fuel you need on hand will depend on the equipment you have, and how frequently you use it. A chainsaw likely will be used less often than a lawnmower for a typical homeowner. It is important to not let fuel sit around for too long, or it can go bad. Two to three months is a typical lifespan for mixed fuel.
For our example, we’ll be mixing about two liters of fuel for a chainsaw, which should be enough for a full season of use. We’re using the metric system as it gives a more precise measurement, but the imperial system is also demonstrated in the above video.
Determine Fuel and Oil Amounts
Now it’s time to do some basic math! The fuel ratio for our chainsaw is 40:1, so 40 parts fuel to 1 part oil. As stated above, we’re going to be mixing 2 liters of fuel. Following the equation in the video, we’ll take 40 divided by 2 liters, which gives us 20. Then to determine the amount of fuel needed, take 1 and divide by 20, which gives us 0.05 liters or 50 milliliters. So, for every 2 liters of fuel, we need 50 mL of engine oil.
Alternatively, you can divide the amount of fuel by 40 to determine the quantity of oil and get the same result. Example: 2 L/40 = 0.05 L or 2000 mL/40 = 50 mL. If using the imperial system, 1 gallon = 128 oz. 128 oz/40 = 3.2 oz. So, for every gallon of fuel, you need 3.2 oz of oil.
Mixing the Fuel and Oil
Now that we have the proper amounts of both fuel and oil measured out, it’s just a matter of filling up our approved fuel storage container. First pour in the fuel, followed by the oil. Give it a good shake and you’re good to go!
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