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

Chainsaw fuel lines can become clogged, crimped, or cracked over time, restricting fuel flow and preventing the engine from starting. This guide will cover the steps to replace fuel lines in common Craftsman, Husqvarna, McCulloch, MTD, Poulan, and Troybilt chainsaws. Before beginning, ensure you are wearing protective work gloves and are in a well-ventilated area.

Chainsaw Fuel Line Replacement Process

Removing the cylinder shield

To remove the cylinder shield, you will need an Allen wrench. This is because the cylinder shield is held in place by screws attached to the engine. Using the Allen wrench, simply unscrew the screws and lift off the shield. It is important to keep the screws safe so that you can reattach the cylinder shield once you have finished replacing the fuel line.

If you do not have an Allen wrench, you can purchase one from most hardware stores. It is worth investing in a set of Allen wrenches of different sizes, as they are a useful tool to have for a variety of DIY tasks. Alternatively, you could use an electric screwdriver with an Allen wrench head attachment.

When removing the cylinder shield, be careful not to scratch or damage the engine. Place the shield somewhere safe where it will not get damaged while you work on the chainsaw. A soft, clean surface such as a cloth or towel is a good place to put the cylinder shield while you work.

It is also important to work in a well-ventilated area when removing the cylinder shield, as you will have just emptied the fuel tank and there may be residual fumes. Good ventilation will reduce the risk of fire and ensure that you do not inhale too many harmful fumes.

Disconnecting the spark plug wire and air filter

Firstly, before you begin any work on your chainsaw, it is crucial to ensure your safety. Make sure the chainsaw is switched off, and it is completely cold. This will prevent any accidental startups and reduce the risk of burns.

Now, let's start with disconnecting the spark plug wire:

• Remove the cover of the chainsaw to access the spark plug.
• Once the cover is off, carefully pull the cap and wire off the spark plug.
• Check the spark plug for any signs of corrosion on the top contact. If there is corrosion, use a wire brush to clean it gently.
• Also, ensure that the area around the spark plug is free from any dirt or debris.
• If you need to remove the spark plug itself (and not just the wire), use a suitable tool to do so. A combi spanner with a large opening or a breaker bar can be used to turn the spark plug anticlockwise and loosen it.
• Be careful not to use excessive force, as this may damage the threads. If the spark plug is tight, you can try using penetrating oil and letting it sit for some time to loosen it.
• Once the spark plug is removed, inspect it for any cracks or carbon deposits. Clean the contacts and electrode with a wire brush if necessary.

Next, we'll move on to disconnecting the air filter:

• Refer to your chainsaw's manual or a trusted source to locate the air filter. It is usually covered by a cylinder cover.
• Remove the cylinder cover to access the air filter.
• Once the cover is off, carefully take out the air filter. It may be attached or seated in a specific way, so make sure to note its position for reassembly.
• With the air filter removed, you can now clean or replace it as needed.

Remember to keep all the removed parts safe and refer to your chainsaw's manual for specific instructions related to your model.

Removing the fuel filter

To remove the fuel filter from your chainsaw, you will need a piece of bent wire, shaped like a "J" hook. This will be used to fish out the filter from the gas tank.

First, ensure there is enough hose for the filter to hang outside the gas tank. Then, use the wire to hook the filter and pull it out of the tank. You may need to be patient with this step, as it can be tricky to hook the filter and remove it without causing any damage. Once you have successfully removed the filter, set it aside and get your new fuel filter ready.

Before installing the new fuel filter, it is important to clean the gas tank, especially if it is contaminated with dirt, sawdust, water, or bar oil. If the tank is dirty, clean it thoroughly and ensure it is completely dry before proceeding.

Now, you are ready to install the new fuel filter. Simply plug the new filter onto the end of the hose, ensuring it is secure. Once the new filter is in place, you can refuel your chainsaw and get back to work!

Remember, fuel filters should be replaced annually or more frequently if they become contaminated. Additionally, always wear nitrile gloves when working on the fuel system to avoid getting dirt or oil on your hands.

Removing the carburetor

To remove the carburetor from your chainsaw, you will need to first work in a well-ventilated area and remove the fuel cap and drain the tank into an approved storage container. Next, use an Allen wrench to remove the screws that hold the cylinder shield to the engine, and lift off the cylinder shield. Then, disconnect the spark plug wire and remove the air filter by pulling off the cover of the air filter housing.

Now, using a 7/16-inch socket, remove the two mounting nuts that secure the carburetor to the engine. Pull the air filter housing off the carburetor. Be careful not to bend the throttle linkage or damage the gas lines. Detach the gas lines from the carburetor using needle-nose pliers. Take digital photos of the throttle linkage and gas line connections for accurate reassembly.

Disconnect the throttle linkage and pull the carburetor completely off the mounting studs. Finally, check the mounting gasket and replace it if necessary.

Removing the old fuel lines

To remove the old fuel lines, first empty the fuel tank into an approved storage container by removing the fuel cap. Next, remove the cylinder shield by unscrewing the screws holding it to the engine with an Allen wrench, then lifting it off. Disconnect the spark plug wire and remove the air filter cover and filter. Now, straighten a coat hanger and bend a hook at the end. Feed this through the mouth of the tank to hook out the cylindrical fuel filter. Cut the fuel line to remove the filter.

Using a 7/16-inch socket driver, remove the two mounting nuts that secure the carburetor to the engine. Pull the air filter housing off the carburetor, then carefully pull the carburetor from the engine block, sliding it along the mounting studs. Be careful not to bend the throttle linkage or damage the gas lines. Take photos of the throttle linkage and gas line connections for accurate reassembly.

Finally, pull the fuel lines off the carburetor and primer bulb using needle-nose pliers. You may need to remove the screws from the primer bulb to fully detach the fuel lines. If you're still struggling, some people have found success with using hemostat pliers, padding the jaws with rubber, or using a wire to pull the lines through.

Frequently asked questions