Replacing Stihl Chainsaw Fuel Line: Step-By-Step Guide

If your Stihl chainsaw is not starting or the engine is dying, it may be time to change the fuel line. The black rubber fuel lines tend to lose elasticity over time, causing them to collapse and reducing or stopping the flow of fuel. This is a common issue that can be fixed by replacing the fuel line. The fuel lines on every Stihl engine contain a main or suction hose and an impulse or return hose. These hoses suck gas from the tank into the carburetor, and any excess fuel returns to the tank to be reused. The lines age quickly due to fuel impurities and must be replaced almost every season. Clogged or dirty fuel lines are also a common cause of engine problems.

Allow the chainsaw to cool before starting work

It is important to allow your chainsaw to cool completely before beginning any work on the fuel line. Chainsaw engines can become extremely hot during operation, and attempting to work on a hot engine can result in burns or other injuries.

Allowing the engine to cool also provides an opportunity to ensure that the chainsaw is switched off and will not start unexpectedly during the fuel line replacement process. This is a crucial safety measure, as a running chainsaw can be dangerous to the user and those nearby.

Additionally, a cool engine will have lower pressure in the fuel tank, reducing the risk of fuel leakage during the replacement process. This is important for both safety and environmental reasons, as spilled fuel can pose a fire hazard and harm the environment.

By taking the time to let the chainsaw cool down, you can help ensure a safer and more controlled work environment for yourself and others. It is always better to be cautious when working with power tools and equipment, and a cooled-down engine provides a more stable and secure starting point for your maintenance work.

Once the chainsaw has cooled, you can begin the process of replacing the fuel line by opening the fuel tank cap and draining the old fuel into an approved container. This step will ensure that you are working with a dry and safe environment, free from the risk of fuel spills or leaks.

Drain the fuel tank

To drain the fuel tank of your Stihl chainsaw, first place the chainsaw on its right side on a flat surface, with the fuel tank cap pointing upward. Remove the fuel cap from the tank, pressing the retainer ring inward to pull it out of the tank. Then, tilt the saw over to drain the fuel out of the tank and into a container.

It is important to use an approved fuel container to catch the fuel. This is because spilled fuel can pose a fire hazard.

Once the fuel tank is drained, return the chainsaw to lie on its right side on your work surface. Insert forceps into the fuel tank and pull out the fuel filter.

Now that the fuel tank is drained, you can proceed to the next steps of replacing the fuel line.

Remove the fuel filter

To remove the fuel filter from your Stihl chainsaw, first place the chainsaw on its right side on a flat surface, with the fuel tank cap pointing upward. Remove the fuel cap from the tank, pressing the retainer ring inward to pull it out of the tank. Tilt the saw over to drain the fuel out of the tank and into a container. Return the chainsaw to lie on its right side on your work surface.

Now, insert forceps into the fuel tank and pull the fuel filter out of the tank. Pull the fuel filter off the fuel line, then return the fuel line to the tank. Turn the chainsaw upright on your work surface. Turn the black knob on the rear of the engine to the left, and pull off the air filter cover.

This process will expose the fuel filter and allow you to remove it from the fuel line. Once the fuel filter is removed, you can proceed to install a new one.

Remove the air filter and air filter cover

To remove the air filter and air filter cover from your Stihl chainsaw, follow these steps:

First, ensure your chainsaw is turned upright on your work surface. Then, turn the black knob on the rear of the engine to the left, and pull off the air filter cover. You can use your hands to do this.

Now, you need to remove the air filter itself. To do this, use a flathead screwdriver to pry the two metal clips upward on each side of the air filter. Once the clips are loose, pull the air filter upward and out of its housing.

With the air filter removed, you can now access the air filter housing. Use an 8mm nut driver to remove the two screws holding the housing in place. Once the screws are removed, simply pull the housing straight off the chainsaw.

At this point, you have successfully removed the air filter and its cover. You can now proceed with replacing the fuel line or performing any other necessary maintenance on your Stihl chainsaw. Remember to always exercise caution when working with power tools, and ensure your chainsaw is turned off and cooled down before beginning any maintenance work.

Lubricate the new fuel line

Lubricating the new fuel line is a crucial step in ensuring the smooth functioning of your Stihl chainsaw. Here is a detailed, step-by-step guide on how to lubricate the new fuel line:

Before lubricating, it is important to prepare the work area and gather the necessary tools and materials. Place your Stihl chainsaw on its right side on a flat, stable surface with the fuel tank cap pointing upward. Make sure you have the necessary tools, such as needle-nose pliers and forceps, and an aerosol lubricant specifically designed for fuel lines.

Now, let's begin the lubrication process:

• Clean the Area: Before lubricating, it is essential to ensure that the area around the fuel tank and carburetor is clean and free of debris. Use a clean cloth or brush to wipe away any dirt, sawdust, or residue that may have accumulated during the fuel line replacement process.
• Prepare the Lubricant: Choose an aerosol lubricant that is suitable for use with fuel lines. It is important to use a lubricant that is compatible with the materials used in the fuel line to avoid any potential damage or issues. Read the instructions on the lubricant carefully and follow any specific directions or precautions provided by the manufacturer.
• Apply the Lubricant: Hold the aerosol lubricant can about 6 to 12 inches away from the new fuel line. Spray a generous amount of lubricant onto the large round area of the fuel line, ensuring that it is evenly coated. Pay particular attention to the curved end of the fuel line, as this is the part that will be inserted into the fuel tank.
• Insert the Fuel Line: After lubricating the fuel line, carefully insert the curved end into the fuel tank. Gently press it inward until the tip of the fuel line appears in the hole by the carburetor. Ensure that the fuel line is securely seated and that there is no risk of it dislodging.
• Connect the Fuel Filter: Before filling the fuel tank, attach a new fuel filter to the straight end of the fuel line inside the tank. Ensure that the fuel filter is securely attached to the fuel line, as it plays a crucial role in preventing debris and impurities from entering the engine.
• Final Lubrication: Once the fuel line and fuel filter are in place, give the fuel line one last coat of lubricant. Use the needle-nose pliers to grasp the tip of the fuel line near the carburetor, and apply a small amount of lubricant to this area as well. This will help ensure smooth fuel flow and reduce the risk of leaks.

Remember to follow all safety precautions when working with fuel and lubricants. Always work in a well-ventilated area and avoid any open flames or sparks. Keep children and pets away from the work area, and dispose of any used materials or rags responsibly.

Frequently asked questions