Replacing The Fuel Line On A Stihl Ts420: A Step-By-Step Guide

The Stihl TS-420 is a hand-held cut-off saw with a two-cycle engine that uses a carburetor for air-fuel combustion. The carburetor on the saw typically only needs maintenance from time to time, but in some cases, it may need to be replaced entirely if it becomes non-functional. This can be done by removing the spark plug wire and spark plug, draining the gas tank, and removing the starter cover bolts and outer case screws. Once the carburetor is exposed, the fuel lines can be disconnected, and the carburetor can be replaced. The fuel lines can then be reconnected to the new carburetor, and the rest of the saw can be reassembled.

Primer bulb to in-tank filter

To replace the primer bulb to in-tank filter on a Stihl TS420, you will need to purchase a replacement primer bulb. You can buy these from a Stihl dealer or online.

The primer bulb is an important component of the fuel system, as it helps to prime the engine with fuel for a smooth and reliable start. The bulb is made of high-quality materials to ensure durability and resistance to wear and tear from fuel exposure.

• Purchase a replacement primer bulb with the part number 4238-350-6201. Ensure it is compatible with your Stihl TS420 model.
• Locate the primer bulb on your Stihl TS420. It is usually found near the fuel tank.
• Inspect the fuel lines connected to the primer bulb. Ensure that they are not damaged or broken.
• Disconnect the fuel lines from the primer bulb. Be careful not to spill any fuel.
• Remove the old primer bulb by gently pulling it out of its housing or unscrewing it, depending on the model of your Stihl TS420.
• Clean the housing or the area where the primer bulb sits. Make sure there is no dirt or debris that could affect the performance of the new primer bulb.
• Take the new primer bulb and carefully insert it into the housing. Ensure it is secure and properly seated.
• Reconnect the fuel lines to the new primer bulb, making sure they are securely attached and not pinched or kinked.
• Test the primer bulb by pressing it gently. It should feel firm and spring back into shape when released.
• Check for any fuel leaks around the primer bulb and fuel lines. If there are no leaks, then you have successfully replaced the primer bulb!

Remember to consult your Stihl TS420 owner's manual for additional information and safety precautions before performing any maintenance or repairs.

Return line from carb to the top of the fuel tank

To change the fuel line on a Stihl TS420, you will need to follow these steps:

Firstly, the primer bulb feed must be connected to the fuel tank's weighted filter. The other line should go back to the top of the fuel tank. Ensure that the fuel line is not broken between the primer bulb and the fuel filter in the tank. Sometimes, the line breaks off at the top of the fuel tank, causing the filter to drop to the bottom of the tank and disconnecting it from the primer bulb. In this case, you will need to replace the fuel line.

The fuel line routing is as follows: Primer bulb to in-tank filter - return line from the carb to the top of the fuel tank.

The Stihl TS420 is a cut-off saw, typically used to cut through hard materials like metal, ceramics, or masonry. It is a hand-held saw with a two-cycle engine that uses a carburetor for air-fuel combustion. The carburetor usually only needs maintenance, but in some cases, it may need to be replaced if it becomes non-functional.

Removing the spark plug wire

To remove the spark plug wire from your Stihl TS420, you will need to wear protective gloves and safety glasses. Ensure the machine is turned off and has cooled down before you begin any maintenance.

First, locate the spark plug cover. This is usually on the side of the engine. Remove the spark plug cover by unscrewing it with a Torx spanner. Now, pull up on the spark plug cap to remove it from the spark plug.

With the spark plug cap removed, you can now disconnect the spark plug wire (the rubber cap connected to the spark plug). Once this is done, you can move on to removing the spark plug itself.

It is important to note that the spark plug wire should not be removed until after the fuel has been drained from the saw.

Removing the gas cap

To remove the gas cap from your Stihl TS420, start by locating the gas cap on the fuel tank. It is usually found on the top or side of the machine. Once you have located the gas cap, follow these steps:

First, ensure that the saw is turned off and cooled down before you begin any maintenance work. Place the machine on a flat, stable surface and make sure there is adequate lighting to see what you are doing.

Next, grip the gas cap firmly with one hand. You may need to use a cloth or glove to get a secure grip if the cap is tight. With your other hand, locate and use the correct size wrench or screwdriver to gently loosen the cap in a counter-clockwise direction. Be careful not to apply too much force, as this may damage the threading on the cap or the fuel tank.

Once the cap is loosened, you can unscrew it by hand and remove it from the fuel tank. Set the gas cap aside in a safe place where it will not get lost or damaged.

Now that the gas cap has been removed, you can proceed with further maintenance or repairs. Remember to keep the work area well-ventilated and always exercise caution when handling fuel or working with power tools.

It is important to consult the owner's manual for your Stihl TS420 for detailed instructions and safety precautions specific to your model. Following the manufacturer's guidelines will help ensure a safe and successful fuel line replacement.

Disconnecting the fuel lines from the carburetor ports

To disconnect the fuel lines from the carburetor ports of a Stihl TS420, you will first need to remove the spark plug wire and then the spark plug itself using a socket set. Next, remove the gas cap and pour the gas from inside the saw into a container.

Now, remove the starter cover bolts with a socket set and pull off the starter cover. Then, remove the outer case screws with a screwdriver, and pull off the case, setting it to one side.

Pop off the air filter cover and remove the air filter. Now, use an Allen wrench to remove the two bolts running through the top of the carburetor. Also, remove the throttle linkage from the side of the carburetor.

At this point, you can disconnect the fuel lines from the carburetor ports. Use a screwdriver to remove the retaining screw holding the carburetor in place.

Frequently asked questions