Is your weed eater slow to start or slow to work? Often a malfunctioning weed eater is due to a dirty or clogged fuel filter. There is good news, though! Cleaning a filthy fuel filter is a simple repair job that will make a big difference in the performance of your trimmer.
How does a string trimmer weed eater work?
It may be helpful to understand how a weed eater works. A little functional knowledge may aid in the use and maintenance of your trimmer.
Operation and Function
Weed eaters are either gas-powered, battery-powered, or electrical. We’re going to look at gas-powered weed eaters in this article since the other types do not need fuel or a fuel filter.
A gas powered weed eater uses a quickly spinning string to trim weeds and grass. It is like a lightweight, handheld lawn mower. Many weed eaters have a 2 cycle engine that runs on gasoline and oil.
You start a weed eater by pulling a cord. This sends a charge via the ignition coil to the spark plug. The spark plug fires as the flywheel turns, which ignites the fuel in the combustion chamber and drives the crankshaft.
The crankshaft is connected to the clutch, which is connected to the driveshaft. When the weed eater is idle, the wings on the clutch are retracted. Once you engage the throttle, the wings spread, engage the driveshaft, and begin to turn the trimmer head.
The trimmer head is on a spindle that connects to the drive shaft. There is a spool that holds the microfilament string and a piece with holes for the string to feed from. The string either feeds out automatically as needed or can advance when the cap is tapped on the ground.
Read the owner’s manual before you operate your weed eater. It’s important to follow operating instructions in order to avoid flooding the carburetor. Make sure to refill the weed eater with the proper size of string.
Weed eaters come equipped with a safety guard to keep debris from flying into your face during operation. Make sure the safety guard is in place before operating the weed eater. The correct ratio of oil to gas for optimal weed eater performance is 40:1.
How do you clean the fuel filter on a weed eater?
A maintenance routine will keep your weed eater operating well for many years! Cleaning the fuel filter regularly is a part of necessary maintenance.
- Gas can
- Needle nose pliers or similar tool
- Dish soap, or another mild soap
- Clean towel or cloth
- Compressed air
1. Remove the spark plug
For safety reasons, it is best to remove the spark plug before working on the weed eater. This will ensure that the weed eater will not accidentally start.
2. Drain the fuel
Make sure your gas can is on a level, stable surface. Insert the funnel in the spout. Remove the gas cap from the weed eater. Carefully tip the trimmer over the funnel and pour the gas into the gas can.
3. Remove the fuel line(s)
Find the rubber fuel line that runs into the gas tank and remove it with a tool, like needle-nose pliers. The fuel filter is located at the end of the fuel line. Remove it from the weed eater. Note that some weed eaters have two fuel lines. One is the fuel suction line, and the other is the fuel return line. If your model has two lines, it is likely that there will only be a fuel filter in the fuel suction line.
4. Clean the fuel filter
You don’t need anything fancy to clean the fuel filter; use a brush, dish soap, and water. Allow the filter to soak in the soapy water for a few minutes. Give it a good scrub and rinse it until the water runs clear.
5. Dry the fuel filter
Get rid of as much excess water as possible. Compressed air is a great way to dry off your filter. Pat it dry with a clean cloth or towel.
6. Reassemble the weedeater
Put the clean filter back in the fuel line. Attach the fuel line to the gas tank. Fill the trimmer with gas, and you’re ready to use the weed eater again!
What are the signs that the fuel filter is dirty?
Look for the following signs to determine if your weed eater is due for a fuel filter cleaning:
- Difficulty starting
- The string moves slower than usual
- The engine sounds slow
What if I need to replace the fuel filter?
The fuel filter is an easy and inexpensive part to replace! If the fuel filter is damaged or impossible to completely clean, purchase a replacement fuel filter and place it in the fuel line. Fuel filters for most brands of trimmers are available on Amazon for $5-$10.
Frequently Asked Questions
Here are the answers to some of your other trimmer related questions.
How do I know if my fuel filter is clogged?
The performance of your trimmer is often an indicator that the fuel filter is dirty. If the trimmer is slow to start or slow to accelerate, check the fuel filter.
Where is the fuel filter on a weedeater?
The fuel filter is located at the end of the fuel suction line attached to the fuel tank. It is about 1-2 inches in length and covered in a mesh or film.
What are the signs you need a new fuel pump?
The fuel pump uses suction to move fuel into the engine. A weed eater will have issues starting or will not stay running if there is an issue with the fuel pump. You may also notice fuel leaking from the trimmer.
Should I remove the spark arrestor screen from my Stihl weed eater?
The spark arrestor screen is a piece of mesh that prohibits large particles from exiting the exhaust. Some homeowners remove the spark arrestor, but I wouldn’t recommend it! You will increase your fire risk without a spark arrestor screen.
What are the signs of a bad fuel injector?
There are several tell-tale signs to look for that may indicate the fuel injector is malfunctioning. The engine will idle rough and may misfire. Often, the trimmer’s engine won’t start at all.
Simple solutions are my favorite! If you are struggling with a cranky weedeater, check the fuel filter first! It may just take a little soap and water to solve your problems. For future maintenance, make sure to clean the fuel filter at the beginning and end of every mowing season.