Replacing Stihl Fs45 Fuel Tank: Step-By-Step Guide

If you're looking to replace the fuel tank on your Stihl FS45, you're in luck! There are a variety of replacement fuel tanks available on the market that are compatible with your model. The process of replacing the fuel tank involves first draining the old fuel, removing the air filter cover, and unhooking the fuel lines. You will then need to detach the fuel tank from the engine by unscrewing the bolts and removing the rubber plugs. Finally, you can install the new fuel tank and reattach the fuel lines and air filter. While this may sound complicated, many users have reported that the process is relatively straightforward and can be completed within a few hours.

How to Replace a Stihl FS45 Fuel Tank

Removing the fuel tank

To remove the fuel tank from your Stihl FS45, start by opening the cap of the fuel tank and draining the remaining fuel into an approved fuel container. You can also run the Stihl to burn off any last remaining fuel.

Next, identify the air filter and remove its cover. There will be fuel hoses behind the air filter's mounting box. You will want to unscrew the bolts holding the starter to the engine and lift the starter away.

Using a screwdriver, remove the tank plugs – there should be two on a Stihl trimmer. Then, remove the screw holding the engine to the fuel tank. Once you've unscrewed it, you can remove the sleeve the screw was sat in.

You can then remove the grommet from the tank by hand. The fuel lines will come out, as well. You can discard these old fuel hoses and the filter.

Now that the tank is out, you can wash it in soapy water. Once it's clean, you can get a good look at the tank to check for holes, cracks, or any other signs of damage. You can also submerge the tank and look for air bubbles, which will indicate punctures. If your tank has any of these problems, it will need to be replaced with a new one.

Draining the fuel tank

To drain the fuel tank of a Stihl FS45, follow these steps:

Firstly, open the cap of the fuel tank and remove the remaining fuel, keeping it in an approved fuel container for safety until proper disposal. You can also run the Stihl to burn off any last remaining fuel.

Next, identify the air filter and remove its cover. Behind the air filter's mounting box, you will find the fuel hoses. Now, unscrew the bolts holding the starter to the engine and lift the starter away.

Using a screwdriver, remove the tank plugs – there should be two on a Stihl trimmer. Then, remove the screw holding the engine to the fuel tank. Once you've unscrewed it, you can remove the sleeve the screw was in.

Now, remove the grommet from the tank by hand, and take out the fuel lines. You can discard these old fuel lines and the filter.

With the tank removed, you can wash it in soapy water to check for any damage. Once it's clean, inspect the tank for holes, cracks, or any other signs of damage. You can also submerge the tank and look for air bubbles, which indicate punctures. If your tank is damaged, it will need to be replaced with a new one. If your tank was merely dirty and is otherwise in good condition, you can reinstall it.

Please note that the fuel lines on Stihl engines age quickly due to fuel impurities and must be replaced almost every season. Clogged or dirty fuel lines can cause common engine problems, so replacing them will help ensure that your engine runs smoothly.

Removing the fuel filter

To remove the fuel filter from your Stihl FS45, you'll need to first open the fuel tank cap and drain all the old fuel into an approved fuel container. You can then pull the fuel filter at the bottom of the tank upward using a metal hook.

Here's a more detailed, step-by-step guide:

• Open the fuel tank cap.
• Drain the old fuel into an approved fuel container.
• Pull the fuel filter at the bottom of the tank upward using a metal hook. You may need to tilt the engine to access the filter.
• Pull the fuel filter off the end of the suction hose.
• Unhook and remove the air filter.
• Remove the two mounting screws holding the air filter box in place.
• Remove the choke cover plate on top of the carburetor.
• Unhook the throttle cable from the choke cover plate.

At this point, you can remove the fuel lines and discard the old fuel filter. Be sure to dispose of the old fuel properly.

Disconnecting the fuel lines

First, open the cap of the fuel tank and drain all the remaining fuel into an approved fuel container. You can also run the engine to burn off any last bits of fuel. This step is important for safety reasons and to avoid spills during the replacement process.

Next, locate the air filter and remove its cover. Behind the air filter's mounting box, you will find the fuel hoses. To access these hoses more easily, you will need to remove the choke cover plate on top of the carburetor and unhook the throttle cable from the choke cover plate.

Now, you can start disconnecting the fuel lines. The fuel lines consist of a main or suction hose and an impulse or return hose. Using your fingers, pull the fuel return hose off the stub next to the spacer flange. Then, pull the fuel suction hose out of its seat on the carburetor.

At this point, both the suction hose and the return hose should be free, and you can pull them out of the engine. Dispose of these old fuel lines appropriately.

As a final step, remove the two tank plugs using a screwdriver. This will completely detach the fuel tank from the fuel lines, allowing you to proceed with the rest of the replacement process.

Remember to be cautious when handling fuel, and always perform these steps in a well-ventilated area.

Installing the new fuel tank

To install the new fuel tank, follow these steps:

Firstly, open the cap of the new fuel tank and fill it with fuel. Ensure that the fuel type is compatible with your Stihl FS45 model.

Now, locate the fuel lines attached to the new fuel tank. These lines consist of a main or suction hose and an impulse or return hose. The suction hose draws fuel from the tank, while the return hose carries any excess fuel back into the tank.

Coat the end of the suction hose with Stihl press fluid. Then, insert the suction hose into the corresponding fuel hole in the engine until the rubber lip is seated securely, and the hose lies flat against the fuel tank.

Next, apply Stihl press fluid to the end of the return hose and insert it into its designated stub until it stops. Ensure that the hose is securely connected.

Connect the other end of the return hose and the suction hose to their respective valves on the carburetor. The suction hose should be attached to the intake valve, while the return hose connects to the outtake valve. Again, apply Stihl press fluid to facilitate a tight seal and prevent leaks.

Finally, reattach the fuel tank to the engine using the appropriate screws. Ensure that the fuel lines are securely connected and that there are no signs of leakage.

With the new fuel tank installed, you can now start your Stihl FS45 and test its performance. Ensure that the engine runs smoothly and that there are no fuel leaks from the tank or hoses.

If you are unsure about any steps or encounter any issues during the installation, it is recommended to refer to the official Stihl FS45 user manual or seek assistance from a qualified technician.

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