Owning and/or operating a weed whacker comes with its own set of challenges. Often, weed whackers seem to have a mind of their own and will randomly act up, like the weed whacker that starts but then dies for no apparent reason, leaving their operators in a pinch. They then have to consider several decisions based on what is practical for them.
When your weed whacker starts and dies, you have three options:
- Purchase a new weed whacker entirely
- Have a professional make the repairs
- Troubleshoot the weed whacker yourself
This article primarily covers what you need to know on how to repair, on your own, a weed whacker that starts and then dies. The good news is, you don’t have to be mechanic to fix your weed whacker. The mechanics of most are fairly straightforward, similar across all brands, and user-friendly. However, you do need to have the right information to avoid potentially costly errors.
Fixing a Weed Whacker that Starts and Dies
If money isn’t an issue for you and forking over another $30 to $300 for a new weed whacker doesn’t faze you, then this may be the right option for you. Just a note of caution: although a weed whacker may come with a larger price tag, it is not a guarantee that you will not end up with the same problem somewhere down the road.
On another note, small hiccups like this come up in the everyday operation of weed whackers fairly frequently. Some weed whackers have more issues than others. Economically, if your weed whacker has been good up until this point, it may be better to repair it rather than to buy a new one with potentially more issues.
Sending Your Weed Whacker to a Professional
On the other hand, if you’d prefer to keep your current weed whacker but aren’t comfortable (or in any way inclined) to do the repairs yourself, hiring a licensed professional to do it for you is a viable alternative. You probably know of Home Depot and may have even bought your weed whacker from this supplier. The good news is, they also offer a weed whacker repair service.
Tool service shops often are local, and vary by area, so be sure to check out other local tool service shops in your specific area for more options. Visiting their website (or store) and reading customer reviews can help you in deciding which repair shop to go with.
On the other hand, be sure to consider the initial price of the weed whacker. It may be more cost-efficient to buy a new weed whacker when compared to the cost of repairs by a professional. Of course, if you were to do these repairs yourself, the cost would be drastically reduced because you’re cutting out the cost of labor (and the parts aren’t that expensive).
Repairing the Weed Whacker, Yourself
I highly recommend trying to repair your weed whacker before moving onto any of the other options. Most of the time, the underlying problem is actually pretty simple. Although it’s not as easy as purchasing a brand-new weed whacker or paying a professional to do the repairs for you, it is well worth it. Here are just a few reasons why:
- Cost Efficient: Because these repairs are often so simple, hiring a professional can be a bit overboard. Most of the parts that you may need are fairly inexpensive and easily found – you can pick them up at pretty much any hardware store.
- Rewarding: Many individuals feel a sense of achievement after doing or fixing something themselves. Although it may be a bit frustrating to find the issue, once you get your weed whacker up and running again, you just might feel on top of the world.
- Saves Time: Because tools are readily available, and you’re relying on your own labor, you don’t have to wait for an extended period of time to pick your weed whacker up (or wait for it to be shipped to you, depending on the shop you chose).
In addition, you need very little to no mechanical skills to complete the repair successfully. I’ll be honest, it may take a little time to figure out what’s going on with your weed whacker if you do it yourself, but I’m going to try to walk you step-by-step through the potential problems. All you need is determination, a desire to learn, the right information (and tools), and a weed whacker with a problem.
Two Different Problems
Please note: if you are having issues with your weed whacker starting altogether, it is different than the current topic of weed whackers that start and then die. The underlying problems are not the same. In the case that your weed whacker does not start at all, I would recommend checking out this article.
Troubleshooting Your Weed Whacker
Fortunately for those of us who own and operator weed whackers, they have very simplistic engines. This means any issues that arise can typically be narrowed down to a few options based on the surface issue.
The first and most important aspect of troubleshooting your weed whacker is to identify the problem. Starting and then dying is merely a symptom, but what is the underlying cause? There are several potential reasons that your weed whacker is doing this. These include:
- Fuel Issues
- Inadequate air intake
- Exhaust issues
- Carburetor
The best way to discover which of the above problems is the issue boils down to trial and error. This is best done by following the fuel path, testing different parts of the engine to find the source.
Please note: this article specifically addresses gas-powered weed whackers. While many of the same rules apply across different brands and models within gas weed whackers, this issue typically does not occur in electric powered weed whackers or trimmer mowers.
Fuel Issues
The first thing to check when troubleshooting is similar to the scenario where you’re searching for your sunglasses only for a kind person to point out that they’re on your head. I’m sure we’ve all experienced something like this. Similarly, if you’re having issues with your weed whacker starting and then dying, start with making sure there’s enough fuel in the tank before anything else. Imagine the frustration you saved yourself from by just checking first.
If there is enough gas in the tank, you can move on from here. What can you do next?
- Check the primer bulb
- Check the fuel line
- Replace fuel in the tank
- Make sure oil-gas mixture in the tank is not too heavy
- Check the fuel filter
These are all likely possibilities that are causing this particular issue with your weed whacker. I will go into detail on each of these potential problems in the following sections.
Primer Bulbs Wear Over Time
Before operating your weed whacker, you always press the primer bulb multiple times to prepare the engine. It is also exposed to various temperature changes, typically stored in garages and sheds throughout the year. Each of these factors eventually wears on the primer bulb, leading to its break down. Make sure your bulb is in good repair and is properly filling.
These are signs that the primer bulb needs to be replaced:
- Dry rot
- Cracking
- Leaking fuel
If you notice any of these issues, replace the bulb (the following video has a great step-by-step instruction for replacing the bulb) and see if the problem of the weed whacker starting, then dying persists. If not, congratulations! You’ve solved the problem pretty quickly. Aren’t you glad you didn’t hire someone to do it for you?
On the other hand, if the start-stop persists, keep reading. There are multiple areas to check for issues further issues, many of which are easy fixes.
The Fuel Line Is the Life of the Engine
A very quick assessment of your weed whacker can give you some useful information. Check to make sure the fuel line is secured. You will typically find the fuel line at the back of the carburetor and close to the primer bulb. There are two tubes, one attaching to the primer and one to the fuel tank itself.
Like the primer bulb, the fuel line becomes brittle over time and will crack and leak, meaning not enough fuel is getting to the engine to keep it running. If this is the case for your weed whacker, it’s time to replace the fuel line. Here (link to Youtube) is one helpful video showing you how to replace the fuel line.
Find Out What Fuel Is in the Tank
Some weathered operators, like Paul Brown, recommend using ethanol-free gas to minimize damage to the engine of your weed whacker. This can extend the life of the engine and improve the way it runs. On the other hand, it can get a little pricey.
For this, you will be primarily looking to find out how long the fuel has been in the tank and if it has been mixed with anything (like oil).
If you’re not sure how long the fuel has been in the tank, your best bet is to replace it with high-quality fuel, such as an ethanol-free one. The main goal is to ensure the gas is not old and stagnant, clogging the engine as it tries to move past idling. In general, the rule of thumb is no more than 30 days.
If you added oil to the fuel, the problem might be that too much was incorporated, making it too heavy to move through to the engine at an adequate speed. If this is the case, you may have to dilute it further by first removing it from the tank (especially if the tank is full) and adding more gasoline.
You may prefer to start over altogether, particularly if the mixture has sat in the tank for too long. With time, the mixture will actually separate back out. If you are adding a premixed fuel to the tank to replace the old, make sure to shake it well if it was not recently made.
Check the Fuel Filter
If the fuel filter is clogged, the weed whacker engine may start, but not enough gas will be able to flow through the filter to keep it running. This is a very simple fix. Before you start, be sure to empty your gas tank. You can watch the details in this step-by-step tutorial on Youtube.
Inadequate Air Intake
Fuel is automatically mixed with air as both enter into the carburetor. If there is not enough air or there is too much air, it can cause problems – such as causing the weed whacker to die right after it starts. This primarily has to do with the air filter. The air filter can either be cleaned or replaced and is easy to access, located the most externally on the carburetor.
If you check nothing else on your weed whacker regularly, check your air filter. Here (link to Youtube) is a video with instructions on how to access and replace the air filter. Be sure to properly attach the cap over the filter when finished cleaning or replacing the air filter, so that the adequate amount of air flows in and out during operation.
Check the Carburetor
The carburetor has a fairly simple design, but it can be a little tricky to work with if you haven’t done your research. It is also one of the most common repairs/adjustments needed when the engine stalls out while idling (i.e., starts, then dies).
There are two screws labeled “H” (high) and “L” that you will need to locate on the carburetor. These coordinate with high speed and low speed. These will need to be adjusted while the engine is idling (likely in short spurts until you are able to keep it running). These features are important to note for each:
- “H” – Controls/adjusts the fuel mixture given when the weed whacker runs at its highest speeds
- “L” – Controls the fuel mixture when the weed whacker is idling.
Essentially, you will need a carburetor tool or an ink pen (see this video on Youtube) to adjust each screw. Some screws may have a slot in it, in which case, you will actually use a flathead screwdriver.
To adjust the screws, you will rotate them each counter-clockwise until the engine speed slows, and then clockwise for the same effect. Find the spot in between each of those points per screw and keep them there. This will ensure the engine works at optimum capacity, with adequate air and fuel supplies.
Exhaust Issues
This problem would probably be the last, and potentially least likely issue you may come across with an engine that starts up but then dies out. Going hand in hand with air intake, your weed whacker needs to release the air flowing through it just like we need to expel the air we inhale. Otherwise, there would be serious consequences.
In the case of a weed whacker, this means a malfunction of the engine. It may start, but the buildup of air would cause the engine to shut down quickly.
The culprit in this is the fuel screen, which becomes gummy over time – especially with frequent use. If you’ve tried all of the other routes, or suspect that this is the root cause, you will need to take apart the exhaust and clean the exhaust screen.
Your Success Story
At this point, you’ve made it through all the options I’ve provided, checking your weed whacker and fixing them as needed. Your weed whacker is likely up and running, and you should feel proud of yourself. I hope you are encouraged to continue investing yourself in this way. It really does pay off in the end.
Persistent Problem
If, for some reason, the same problem is persisting, check to make sure you’ve made the correct adjustments to parts like the air filter, which are very sensitive to things like airflow.
If the problem remains or has become worse, I recommend taking your weed whacker into a professional. As frustrating as all the time and energy you’ve put may be, there is likely something deeper going on with the engine. Unless you are a mechanic or experienced with the engine of a weed whacker, at this point, it is better to save yourself any further frustration and let an experienced repairman take over.
In most cases, you probably only had a few minor repairs to make. It is unlikely that you reach the point of needing to take your weed whacker into a repairman after you’ve made adjustments and replacements yourself.
I hope this information was helpful. Happy weed whacking!