Stihl Backpack Leaf Blower: Replacing Fuel Gaskets

If your Stihl leaf blower is leaking gas, you may need to change the fuel gasket. To do this, you will need to take the leaf blower apart and check the fuel lines and tank for any obvious leaks. If you cannot find any leaks, the connection between the airbox and the carburettor may be to blame. The metering diaphragm in the carburettor is a likely suspect, so pull the carb, take off the covers and check if the gaskets are hardened. If the fuel pump gasket is not sitting perfectly flat against the body of the carburettor, it will need to be replaced.

Check for leaks

To check for leaks, start by examining the fuel lines and tank for any obvious signs of leakage. This includes checking all sides of the tank. Additionally, inspect the connection between the airbox and the carburettor, as well as the area around the spark plug, for any traces of moisture or wetness.

If no visible leaks are detected, perform a test blow by filling the tank halfway and rechecking for leaks. Observe the equipment for a few days, as some leaks may not be immediately apparent. If the problem persists, the metering diaphragm in the carburettor could be the culprit.

Remove the carburettor covers and inspect the gaskets. The fuel pump gasket should sit perfectly flat against the body of the carburettor, and any distortion, hardening, or swelling of the metering diaphragm indicates the need for a replacement. Ensure that the diaphragm remains soft and flexible.

Finally, check the muffler, as fuel could be ending up there instead of leaking externally.

Examine the connection between the airbox and carb

To examine the connection between the airbox and the carb on your Stihl leaf blower, you will first need to remove the air filter cover. This is usually done by unscrewing a few screws. Once the cover is off, you can inspect the air filter and the surrounding area for any signs of damage or leaks.

If you notice any tears or holes in the air filter, it will need to be replaced. Also, check the area where the air filter cover connects to the airbox for any signs of leaks. If the seal between the cover and the airbox is damaged or worn, it may need to be replaced as well.

Next, you will need to inspect the carb itself. The carb is usually located near the airbox, and it is the component that mixes the fuel and air before it enters the engine. Again, look for any signs of leaks or damage. Pay close attention to the gaskets and seals on the carb, as these are common sources of leaks. If the gaskets are hardened, swollen, distorted, or cracked, they will need to be replaced.

Finally, check the connection between the airbox and the carb. This area can be prone to leaks, so look for any signs of fuel buildup or wetness. If you notice any leaks, you may need to replace the gasket between the airbox and the carb. This gasket needs to sit perfectly flat and seal properly to prevent leaks.

Inspect the fuel float in the carb

To inspect the fuel float in the carb of your Stihl leaf blower backpack, follow these steps:

Firstly, locate the carb. If you are unsure where it is, refer to your Stihl leaf blower backpack manual or seek advice from a Stihl dealer or a small engine repair specialist. Once you have located the carb, you will need to remove it from the blower.

After removing the carb, you can begin inspecting the fuel float. Carefully examine the fuel float for any signs of damage or wear and tear. Look out for any cracks, leaks, or blockages. Pay particular attention to the needle and spring mechanism, as these parts are crucial for the proper functioning of the fuel float. If the needle is stuck open, it can cause the fuel to drain from the tank.

Next, check the gaskets and diaphragms in the carb. Ensure that the gaskets are not hardened or distorted. They should be soft, flexible, and sit perfectly flat against the body of the carburetor. If the gaskets show any signs of swelling, hardening, or distortion, they will need to be replaced.

Additionally, inspect the metering diaphragm. It should be soft and flexible. If it appears swollen, distorted, or hard, it will need to be replaced. You can find the appropriate STIHL repair kit for your leaf blower model by referring to the parts listing.

Finally, clean the fuel float, needle, and spring mechanism with a suitable cleaning solution. Ensure that all parts are free of dirt, debris, and carbon buildup. Reassemble the carb and leaf blower according to the manufacturer's instructions.

By following these steps, you can thoroughly inspect the fuel float in the carb of your Stihl leaf blower backpack and ensure that it is functioning correctly.

Check the diaphragms in the carb

To check the diaphragms in the carb of your Stihl leaf blower, you'll first need to remove the carb. Take off the covers and inspect the gaskets. The fuel pump gasket should sit perfectly flat against the body of the carburetor. The metering diaphragm should be soft and flexible. If it is swollen, distorted, or hard, it will need to be replaced.

If you have a C1Q-S209 carburetor, the STIHL repair kit is part number 4228 007 1051. If you have a 4244/11 carburetor, you'll need part number Z000 003 K035.

When replacing the diaphragms, it's also a good idea to clean the jets and check for blockages in the fuel lines.

Clean the jets

To clean the jets of your Stihl leaf blower, you'll need to remove the carburetor and clean it with a carb cleaner. Here's a step-by-step guide:

Step 1: Uninstall the Carburetor

First, empty the carburetor. Then, use a handheld screwdriver to uninstall the carburetor. Disassemble the carburetor and check the carb kits.

Step 2: Clean the Carburetor

Use a carb cleaner to spray on the clog of the carburetor. You don't need to do anything else after this step—the spray will work when you run the leaf blower.

Step 3: Reinstall the Carburetor

Reassemble the carburetor parts and reinstall it.

Notes:

• If the dirt blockage cannot be cleaned or the carburetor has any cracks on it, you'll need to go to a technician or install a new one.
• Regular maintenance, cleaning after every use, and replacing the filters once a year are important for keeping your leaf blower running at its best.

Frequently asked questions