Replacing Fuel Lines On Stihl String Trimmers: A Step-By-Step Guide

String trimmers are an essential tool for lawn care and landscaping, but they require regular maintenance to keep them in good working condition. One common repair task is replacing the fuel lines, which tend to break down and become brittle over time due to prolonged contact with fuel. This guide will provide a comprehensive overview of the process for replacing the fuel lines on a Stihl string trimmer, covering everything from the tools required to step-by-step instructions for a safe and successful fuel line replacement.

Drain old fuel into an approved container

To drain old fuel from your Stihl string trimmer into an approved container, you will first need to open the fuel tank cap. This will allow you to access the fuel and begin the draining process.

Once the cap is open, you can start draining the fuel by carefully tilting the trimmer to allow the fuel to pour out into the approved container. It is important to do this slowly and with caution to avoid any spills or messes. Make sure you are wearing appropriate protective gear, such as gloves and eye protection, to safeguard against any fuel coming into contact with your skin or eyes.

If your trimmer has a fuel filter, you may need to use a metal hook to remove it. Place the metal hook under the fuel filter and gently lift it up and out of the tank. This will ensure that the fuel filter does not get in the way or obstruct the flow of fuel during the draining process.

As the fuel is draining, keep an eye on the container to ensure it does not overfill. Approved fuel containers usually have markings or indicators to show the maximum safe fill level. If the container reaches this level, stop pouring and set the container aside in a safe place. Then, retrieve an additional approved container to continue draining the remaining fuel.

Once you have successfully drained the old fuel, you can proceed to the next steps of replacing the fuel lines on your Stihl string trimmer.

Remove the fuel filter

To remove the fuel filter from your Stihl string trimmer, you will first need to drain all the old fuel from the tank into an approved fuel container. You can then pull the fuel filter at the bottom of the tank upwards using a metal hook.

Once you have done this, pull the fuel filter off the end of the suction hose. The fuel filter line will likely have a couple of extra pieces holding it in place, such as a small retaining ring on the outside of the fuel tank. This can be removed with a screwdriver.

The rest of the old fuel filter line and the fuel filter can be thrown away. Instead of trying to pull the line through the fuel tank hole, it is much easier to cut the line and push the old fuel filter into the tank. You can use a pair of flush-cut diagonals to cut the line.

Remove the air filter

To remove the air filter from your Stihl string trimmer, start by removing the air filter's cover. This will expose the air filter and the mounting screws holding the air filter box in place.

Using an appropriate tool, unhook the air filter from its housing. With the air filter loose, you can now remove the mounting screws holding the air filter box in place.

Once the mounting screws have been removed, carefully lift and remove the air filter box from the engine compartment. Be sure to set it aside in a safe place, as you will need to reinstall it later.

With the air filter box removed, you will now have access to the choke cover plate, which is located on top of the carburetor. Removing this plate will allow you to access the fuel system and carburetor for further maintenance or repairs.

Now that the air filter and its housing have been removed, you can proceed with the next steps in your fuel line replacement or other maintenance tasks on your Stihl string trimmer.

Remove the choke cover plate

To remove the choke cover plate on top of the carburetor of your Stihl string trimmer, you will first need to remove the air filter cover and then unhook the air filter. You can then remove the choke cover plate.

To remove the air filter cover, you will need to remove the two mounting screws holding the air filter box in place. Once these are removed, simply lift the cover away from the engine.

With the air filter exposed, you can then unhook it. It may be helpful to use a screwdriver to carefully unhook the filter.

Now that the air filter is unhooked, you can remove the choke cover plate. It should lift away easily, but be careful not to damage any of the surrounding components.

With the choke cover plate removed, you will now be able to access the carburetor and begin the process of replacing the fuel lines.

Remove the fuel tank, carburetor, fuel lines and carburetor mount plate

To remove the fuel tank, carburetor, fuel lines and carburetor mount plate, you will need to disassemble the trimmer to access its entire fuel system. The first step is to remove the fuel system cover, which is located on the rear of the engine. Remove any fasteners that are affixing the cover to the engine.

Next, you will need to unscrew the carburetor fasteners. The carburetor will be affixed to the engine against a plate, which may be called a carburetor choke plate. You will need to release any fasteners on the carburetor.

The third step is to release the throttle cable from the carburetor. Simply lift and tilt the carburetor to release the cable. Now, unscrew the fasteners that are holding the mount plate in place.

Finally, remove the fuel assembly from the trimmer. The fuel tank, carburetor plate, and carburetor will still be connected by the system's fuel lines. Remove them together before detaching the fuel lines.

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