Ryobi Weed Wacker Won't Stay Running? (Possible Causes & Fixes)

Benjamin Wright
by Benjamin Wright
You can typically depend on a Ryobi weed wacker to work consistently and without problem, but they can sometimes be tough to keep running. Your Ryobi weed wacker may have trouble running consistently if there is a problem with the carburetor or airflow. Whether it be fixing the carburetor or adjusting the fuel intake, let’s explore the solutions to a Ryobi weed wacker that won’t keep running.

When it comes time to perform maintenance on your yard with your new Ryobi weed wacker, there are few things as annoying as a weed wacker that won’t stay running. For many, diagnosing the problem and then finding a solution can be an arduous task. However, the solution is often simpler than many think.

When your Ryobi weed wacker won’t stay running, the problem is usually based on fuel or airflow and can be solved by either adjusting the carburetor or replacing any damaged parts that make up the fuel system. A carburetor rebuild, fuel intake adjustment, or part replacement can solve the problem.

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Carburetor Problems

If the problem is related to the carburetor, here are some steps that will likely fix most problems you are having with your Ryobi trimmer:

before you start, remember that your first steps should always involve assessing the problem in order to minimize the amount of unnecessary steps. A complete carburetor rebuild will certainly solve the problem in most cases. However, most of the time you can get your weed trimmer running again with some simple adjustments, a cleaning, or a couple of spare parts.

It should be noted that when we say “carburetor” we are also referring to all the parts and systems that are connected to and dependent on the carburetor.

Here are some places to begin when you begin troubleshooting.

Fuel Issues

A commonly overlooked problem affecting weed eaters is the quality of the fuel in the gas tank. When the gas in your string trimmer is either old or contaminated, that fuel can have adverse effects on the performance of your string trimmer. Always be sure that you have fresh gasoline in your fuel tank.

Check Your Air to Fuel Ratio

within the carburetor of your string trimmer, air and fuel are continuously mixed during operation. The ratios of fuel to air differ depending on how hard the machine is working. There is an ideal ratio for low speeds as well as for high speeds. If you suspect that the fuel to air ratios are causing your problem, look for two small screws on the carburetor.

One of the screws is designated for adjusting the ratio for low-speeds and the other is for high-speed operation. Adjust each screw until an optimal speed is reached at both levels. Too slow or too fast can a string trimmer stalling during operation.

Check Your Choke

Another common issue that people have is not knowing how to use the choke. The choke is responsible for supplying fuel to the engine while starting from a dead stop. The choke should be engaged fully when starting but should then be moved to the off position when the string trimmer is running. If you are, unsure as to how to use the choke on your particular model, it is always a good idea to refer to the owner’s manual.


A string trimmer can also stall during operation when the air filter gets dirty. Without enough airflow, proper combustion is not possible. The engine also has trouble running when the exhaust cannot escape. Fortunately, if this is the root of the problem, an air filter is both easy and inexpensive to replace.

Gas Cap

It may seem strange to some, but the gas cap can also be a likely culprit when your string trimmer stalls during operation. There is an air vent built into most gas caps which allows for proper fuel flow during operation. When the vent is blocked by dust, dirt, or debris, fuel flow is hindered.

Inversely, too much airflow can also be a problem. This happens when cracks occur in the cap or when the seal around the threads is broken. To solve either problem, replacing the gas cap is advisable. To see if a replacement is necessary, try running the trimmer with a loose cap and observe its performance.

Battery Problems

If the problem is related to a battery, here are some things that you can do to get you Ryobi weed wacker running well again:

The Ryobi 40v weed wacker and others like it are very popular gardening tools. The battery provides easy maintenance than what you get with a gas-powered trimmer. Battery-powered trimmers are also lighter and more convenient to use.

Despite the benefits, issues do come up with battery-powered weed wackers, from time to time. If your battery-powered string trimmer is having trouble staying in a powered state, the problem is most likely related to the battery.

The 40v battery that powers many of the trimmers in the Ryobi lineup is a great battery when it is working. The problem is, there are a few things that can cause the battery to fail. The two most common reasons for a 40v Ryobi battery to stop working as it should are overexertion and over depletion.


When overexertion is the cause of the problem, many users experience problems with their weed Wacker when doing heavy tasks or using the trimmer at full power. While it is fine to but run the weed whacker to its limits in short spurts, the Ryobi cannot handle it as well as some other weed eaters. Pushing the trimmer too hard overheats the battery and causes a safety shutoff to engage. When this happens, many users begin to experience stalling during operation.

Over Depletion

Over depletion is another leading cause of continued battery issues. There is a point of depletion when battery chargers will not correctly read and respond to the Ryobi 40v battery when plugged in. When this is the case, the battery charging unit will not charge the battery no matter how long the battery is cradled.

To understand if this is the problem affecting your battery, check the lead lights. If you see a steady green light and a flashing red light additional steps will be required to get your battery charging again.

An easy way to fix this problem is to put the battery on the charger for short intervals, allowing the charger to provide short bursts of energy to the battery. Replacing the battery several times in a row can provide enough of a charge for the battery charger to begin reading and charging the battery once again.

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Related Questions

Why won’t my Ryobi weed whacker run at full speed?

Any time a weed whacker runs at reduced speed, the issue is usually connected to either an air or fuel flow issue in the carburetor.The reduced power sometimes comes when running the weed whacker at full speed or right when you start the string trimmer. In either case, clearing the carburetor will usually fix the problem.

Why does my wire trimmer die when throttled up completely?

Many new weed whackers come tuned for reduced power. While not always the case, the reduction of power can sometimes cause a weed whacker to die when throttled up completely. To fix the problem, acquire the appropriate tool and adjust the Carburetor.The tool that you will need to do this is readily available at many online retailers and is inexpensive in most cases. One thing to keep in mind is that different string trimmers will require a different sized tool, so when unsure about which size you will need, buying a full set can save you some time.

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Benjamin Wright
Benjamin Wright

Benjamin is a proud homeowner who loves to write about DIY projects and home improvement projects. Traveling, perfecting his home, and spending time with his family are just a few of the many things that keep him inspired.

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