This Is the Type of Gas and Oil Ryobi String Trimmers Use

by Jack Grover
person trimming grass
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You must use the correct type of gas and oil to keep your trusty Ryobi string trimmer running smoothly.

Like a secret potion that fuels its performance, this dynamic duo ensures optimal operation and longevity.

On the market, there are two-stroke and four-stroke models of Ryobi string trimmers — each requiring specific care.

For those using a two-stroke trimmer, a mix of gas and two-stroke engine oil is the key. Just pour in approximately 2.6 ounces of oil for every gallon of fuel and shake the gas can to guarantee thorough mixing before filling up the engine.

Four-stroke trimmers have separate fill ports. Because of that, they require adding oil and gas separately. For those models, Ryobi recommends 20W-50 engine lubricant or compatible alternatives.

Here’s an in-depth look into the best combination of oil and gas for Ryobi string trimmers.

Gas and Oil Mixture

When it comes to the gas and oil mixture for Ryobi string trimmers, following the specific instructions outlined in the manual is essential. It’s the only way to guarantee the optimal performance and longevity of your trimmer.

The type of engine your Ryobi trimmer has determines whether you need two-stroke or four-stroke oil.

For two-stroke models, there is no oil crankcase or oil cap. Instead, you’ll need to mix the oil with gas and pour the mixture into an approved container.

Most two-cycle oil containers have standard markings for a 50:1 gas/oil mixture. If your oil container doesn’t have level markings, you can use a measuring cup to measure the oil volume accurately.

The gasoline you use should be 87-octane or better.

To thoroughly mix the oil with the fuel, give your gas can a good shake.

For four-cycle trimmers, check the oil level by removing the oil cap and cleaning off the dipstick.

If it’s below the bottom mark, you’ll need to add some more oil incrementally until it reaches flush with the top mark on the dipstick.

Two-Stroke Trimmers

As mentioned above, to properly fuel your two-stroke trimmer, you’ll need to mix the gasoline and oil in the correct ratio for optimal performance. Most two-cycle oil containers have standard markings for a 50:1 gas/oil mixture.

The table below shows how much oil you should use, depending on the amount of gas you want to add.

Gas to Oil Mix Ratio1 Gallon Gas2 Gallon Gas2.5 Gallon Gas
50:12.6 oz Oil5.2 oz Oil6.4 oz Oil
32:14 oz Oil8 oz Oil10 oz Oil

Here are some things to keep in mind when mixing fuel for your Ryobi two-stroke trimmer:

  1. Open the oil container and pour the oil into it. Make sure to use a measuring cup if the container doesn’t have level markings.
  1. It’s better to add the gasoline after the oil to ensure a better mix.
  1. Shake the gas can thoroughly to ensure the oil is well mixed with the fuel.
  1. You can mix more than 1 gallon of fuel at a time, but do it in increments of 1 gallon so you can take advantage of the oil container markings.

Four-Stroke Trimmers

Four-stroke trimmers require oil to be added independently of fuel, unlike their two-stroke counterparts.

Ryobi recommends using their four-cycle 20W-50 engine lubricant or other suitable engine oils for their four-stroke trimmers.

When choosing the right oil, make sure it meets API standards under the SJ service category. Avoid using non-detergent or two-stroke engine oils, as they’re formulated differently.

Let’s dive into the best options you have.

  • First on the list is SAE 20W-50. This type of oil is commonly recommended for engines operating under higher temperatures or heavy load conditions. 
  • Next up, we have SAE 30W. This oil is ideal for warmer temperatures and provides a thicker viscosity that offers excellent engine protection.
  • SAE 10W-30 and SAE 10W-40 are also suitable choices. These multi-viscosity oils perform well in varying temperatures, making them versatile and practical choices.

It’s recommended to change the oil in your four-stroke trimmer after every 25 hours of use. Neglecting regular oil changes can lead to issues such as oil sludge buildup and potential engine damage.

To change the oil, simply remove the top and bottom engine covers, unscrew the oil cap, let the old oil drain into a container, then add new oil. Finally, replace both covers and screw back on the oil cap securely.

Recommended Oil Options

oil bottle

For optimal performance and longevity of your trimmer, choose the right oil options suitable for different temperature ranges and climates.

The oil options available for Ryobi four-cycle weed eaters include SAE 20W-50, SAE 30W, SAE 10W-30, and SAE 10W-40.

The recommended choice for best performance is SAE 20W-50. This oil is especially suitable for warmer climates as it doesn’t thin in higher temperatures. If you live in a warmer climate or plan to use your trimmer during the spring/summer seasons, SAE 30W would also perform well.

If you reside in a colder climate or will be operating the trimmer in cold temperatures, consider using SAE 10W-30. It flows well when cold and has the same thickness as SAE 30W when the engine is hot.

Alternatively, if you need an oil that performs well across varied temperatures, opt for SAE 10W-40. It’s thinner than SAE 30W and performs better up to temperatures reaching up to 104°F.

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Changing the Oil

Changing the oil in your trimmer is an essential maintenance task that ensures proper lubrication and prevents engine damage.

Here are the steps to follow when changing the oil:

  1. Start by removing the top and bottom engine covers of your trimmer. It will give you access to the oil cap and drain plug.
  1. Unscrew the oil cap and place a container underneath to catch the old oil as it drains out. Make sure to dispose of the old oil properly, following local regulations.
  1. Once all the old oil has drained, it’s time to add new oil. Be sure to check your owner’s manual for specific instructions regarding the amount of oil needed.
  1. Slowly pour in the new oil, making sure not to overfill. It’s always better to add a little at a time and check the level using the dipstick than to risk overfilling.
  1. Add a fuel stabilizer so your gas lasts longer without breaking down.
  1. After adding new oil, replace both engine covers and securely tighten them.

Following these simple steps, you can keep your trimmer well-lubricated and ready for action.

Final Thoughts

So there you have it, folks!

Using the right gas and oil is the secret to keeping your Ryobi string trimmer running smoothly. It’s like a match made in heaven.

If you own a trimmer with a two-stroke engine, remember about the 50:1 gas-to-oil ratio.

Whether you have a two-stroke or four-stroke model, follow Ryobi’s recommendations for the perfect fuel mix. Doing so will help you keep your machine in tip-top shape.

And don’t forget to regularly check that oil level because we all know nothing says ‘fun weekend’ like a trimmer that won’t start.

Happy mowing!

Frequently Asked Questions

What are the differences between a two-stroke trimmer and a four-stroke trimmer?

Two-stroke trimmers require a mixture of gas and two-stroke oil, while four-stroke trimmers have separate compartments for gas and oil. Two-strokes also don’t have an oil crankcase or cap, but four-strokes do.

Can I use any type of oil in my Ryobi trimmer, or are there specific oil requirements?

You can’t use just any type of oil in your Ryobi trimmer. It’s best to follow specific oil requirements based on whether your trimmer has a two-stroke or four-stroke engine since using the wrong oil can lead to damage.

How often should I check the oil level in my Ryobi trimmer?

Check the oil level in your Ryobi trimmer regularly to ensure it’s at the correct level. Neglecting oil checks can lead to engine damage.

For best performance, checking the oil after every 25 hours of use is recommended.

What are the consequences of neglecting oil changes in my Ryobi trimmer?

Neglecting oil changes in your Ryobi trimmer is like running a marathon without water. It can lead to engine damage, oil sludge buildup, and decreased fuel efficiency. Ultimately, it might shorten the lifespan of your trimmer or lead to irreparable damage.

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