Stihl Leaf Blower Not Running Full Speed

Did your Stihl leaf blower not running full speed? The most common reason behind a leaf blower is not working in full power can be clogged air filters, fuel filters, broken fuel lines, carburetors, or spark arrestor issues. If you have some DIY, you can easily get rid of these issues of your own.

Stihl-brand leaf blowers are specially designed with minimal design and are very simple to use too.Please do not panic about it when it’s showing the issues or not blowing at full speed. Luckily, they can be solved with a bit of troubleshooting.

Here, you will find all the reasons that cause your Stihl leaf blower not to work properly and their possible solutions. So let’s start our discussion.

Why Stihl Leaf Blower Not Running Full Speed

When your Stihl leaf blower doesn’t start or run at full speed, you need to find the problem first.There are factors that can cause your leaf blower to stop working properly. The most common problem with the blower is its filter system, carburetor, and Spark arrestor.

Check if Stihl bg 86 problems are clogging or cracks in the fuel tank, carburetor, or fuel line. If there is any, you can fix this on your own.

Have  a look at the reasons and their possible solution listed in the table below

Causes Stihl Leaf Blower Not RunningPossible Solutions
Air filter issueClean the filter
Fuel filter issueCheck and clean the filter
Carburetor issueClean it or install a new kit
Spark arrestor issueRegular maintenance needed
Clogged or Damaged Fuel line issueClean or replace with a new one

These are some common issues that can cause your leaf blower to idle and not run fast. Did you find which one of these issues you are facing with your Stihl leaf blower? If not, try to find out the leaf blower issue and fix it with the solutions we described here.

Problem 1: Dirty and Clogged Air Filter Issue

The first thing you should check for is the air filter of the leaf blower. This is the most crucial part of a leaf blower. It allows the external air to flow into the engine and cool the engine.

A leaf blower’s air filter helps to filter the derbies and dust that comes with the air. It helps to protect the engine from the dirt that can harm the blower.

After a long time of use, the filter gets clogged up with dirt. It is the most common cause of a leaf blower not running at full speed. That prevents enough air from flowing to the engine. The blower starts to lose its efficiency.

Troubleshoot For the Air Filter

The possible solution to make your leaf blower work again is to clean or replace the air filter. To clean or replace the filter, you have to follow the steps below:

Step 1: Remove the Air Filter Cover

First, you have to locate the air filter cover of your leaf blower. Then take a screwdriver and remove a knob or a screw.

Step 2: Check the Filter

After removing the cover, then check for the air filter under it. Check if it is damaged or clogged with debris. If the filter is clogged with dirt, you can clean it and use it again. On the other hand, if the air filter is damaged, it needs to replace with a new one.

Step 3: Clean The Air Filter

Usually, the leaf blower has a foam filter. If it is not torn or damaged, you can wash it with soap water. To wash the filter, take lukewarm water and soap. Wash the filter gently. After washing, you need to dry the filter completely.

Step 4: Reinstall & Close The Air Filter Cover

Finally, it is time to reinstall the clean one or a new air filter to the leaf blower. Air filters are not so expensive, so you can easily replace them with old ones. Place the air filter and install the air filter cover again in its place.

Note: It is an incredible idea to check your leaf blower filter before every time you take it out of the store after a long time.

Problem 2: Fuel Filter Issue

If there is no problem with your air filter, the next thing you have to check is the fuel filter. This filter is placed between the tank and the carburetor of the leaf blower.

A fuel filter helps prevent the fuel tank debris from going through the tank to the engine. When this fuel filter is clogged with dirt, it prevents the fuel from reaching the engine.

It can happen when fuel remains in the tank or line for a long time. Because of the clogged fuel filter, the carburetor can not receive enough fuel and loss power.

Troubleshoot for the Fuel Filter

The possible solution for a clogged fuel filter issue is to clean it. If the filter is cracked or damaged, replace it with a new one. To check the fuel filter of your Stihl leaf blower, you can follow the steps below:

Step 1: Drain The Old Fuel

First, to get the filter, you have to drain the old fuel to remain in the fuel tank for a long time. The fuel filter is placed inside the tank.

Step 2: Separate The Tank

Take a screwdriver to open separate the tank from the fuel line. Then disconnect the spark plug to prevent any accident. Remove the filter and check for crack or damage.

Step 3: Clean the Filter

If there is no crack on the filter, then clean the filter with soap or detergent and warm water. After cleaning, dry the filter before reinstalling it.

Step 4: Install the filter

Again place the filter in its place. Or put a new filter in the position of the old one. Then reattach the spark plug and fuel line.

Note: Manufacturers suggest using a commercial premix fuel to prevent damage to the filter and replacing the fuel filter once a year.

Problem 3: Clogged Or Damaged Fuel Line Issue

A damaged or clogged fuel line can be another cause of the gas leaf blower losing power. It connects the fuel tank to the carburetor and supplies fuel from the tank to the carburetor.

If the line gets damaged or cracked, it can’t supply enough fuel to the carburetor. It can be clogged with the dirt that came from the tank. This can also happen with a bend in the pipe. These can prevent it from working correctly.

Troubleshoot the Fuel line

The possible solution for a cracked, torn, or clogged fuel line is to replace it with a new one.

Step 1: Locate the fuel line

To check and replace the line, first, locate the fuel line. It is connected with the fuel tank of the blower.

Step 2: Disconnect the pipe

Take a screwdriver, unscrew the screw connecting the line with the tank, disconnect the fuel line from the tank. Then disconnect the spark plug.

Step 3: Install A New Line

Now take a new fuel line, screw it with the tank and the carburetor. And finally, connect the spark plug. The leaf blower will start to work again.

Problem 4: Clogged Spark Arrestor

Nest you should check for the spark arrestor. The Spark arrestors are placed in the engine. It has screens that help to prevent the spark or debris from escaping from the engine. It also helps to minimize the sound of the leaf blower.

After a long time, use the arrestor start to deposit carbon from the engine exhaust gases. When the spark arrestor gets clogged with debris, it prevents the exhaust gases from getting out of the engine. Then it causes the leaf blower may not to work properly.

Troubleshoot the Spark Arrestor

If the problem is with the spark arrestor, You can check it. You can get rid of the clogged spark arrestor by cleaning or by installing a new one.

To clean or replace the spark arrestor of your leaf blower, you can follow the steps below:

Step 1: Search For Spark Arrestor

First, you have to make sure about the location of the spark arrestor. Usually, you can find it inside the muffler.

Step 2: Remove The Spark Arrestor

First, disassemble the spark plug, then remove the outer cover of the leaf blower engine. Then remove the muffler cover with the help of a screwdriver. You will find the spark arrestor.

Step 3: Check The Spark Arrestor

After removing the arrestor, check it for any damage or clog in it. If the screen becomes clogged with the carbon deposit, it becomes black, and you can’t see through it, then the screen needs to clean and used again. Otherwise, if the screen has any torn or damaged, you can replace it.

Step 4: Clean Muffle and Arrestor Screen

You can clean the muffle and the arrestor screen in two ways

The first way to clean the muffle and the arrestor screen is with soap. To do this, you need a hard brush, soap, and lukewarm water.

The second way to clean the arrestor screen and muffle it is to burn them on a blow torch. In this process, the clogged derbies of the muffle and the screen get burned and cleaned.

Step 5: Reinstall Or Replace The Screen

If you can not clean the clogged debris either way, then it’s time to replace it. An arrestor screen is not expensive to install a new screen in your leaf blower.

Problem 5: The Carburetor Issue

If your air and fuel filters, fuel tank, or spark arrestor are not clogged, finally, it’s time to check the carburetor. A carburetor is another most essential part of a leaf blower. It supplies the fuel and air mixture that enters the engine and controls its ratio. 

The problem can occur with a carburetor too. Sometimes, the carburetor itself may be clogged with debris or cracked or has any problem with the adjustment. Because of them, the carburetor may become hot. A Leaf blower loses power when it is hot.

Troubleshoot for the Carburetor

First, check the carburetor to make sure what kind of issue you are facing with it. If the carburetor is dirty, you can clean it on your own and use it. When there is any crack or damage in the carburetor, you need to install a new carburetor.

There is also an adjustment problem with the carburetor. You can fix this by tuning it in the correct adjustment.

Step 1: Uninstall the Carburetor

First, empty the carburetor. Then with a handheld screwdriver, you can uninstall the carburetor easily. Then disassemble the carburetor and check the carb kits.

Step 2: Clean It With Carb Cleaner

Use carb cleaner recommended for cleaning the carburetor. Spray it on the clog of the carburetor. You need not do anything after that. The spray will work when you run the leaf blower.

Step 3: Reinstall it

Reassemble the carburetor parts and reinstall the carburetor.

Note: If the dirt blockage can not be cleaned or the carburetor has any crack on it, you need to go for a technician or install a new one.

This Video Will Help You Too!

Frequently Asked Questions (FAQs)

Why Is My Stihl Blower Not Blowing Hard?

The Stihl blower may not blow harder if the blower fan is broken or loose. Tighten the fan if it is loose, or you have to replace the fan if it is broken.

Why Does My Leaf Blower Die At Full Throttle?

A leaf blower will die at full throttle if the air filter, the fuel filter, muffle, spark arrestor, or the carburetor jets are clogged with derbies.

How Can I Make My Stihl Blower Run Better?

For running your Stihl leaf blower better, it needs regular maintenance, cleaning after every use, and replacing the filters once a year.


After you store your leaf blower for a long period, you will notice the Stihl leaf blower not running full speed. Even you can fix it if you are not a technician expert.

Running a leaf blower at its full strength for life long requires regular maintenance and cleaning. We have described here the cleaning and maintenance process of a Stihl leaf blower. You should go for a technician through regular maintenance if you face any problem with your leaf blower.

Think this article becomes helpful for you to find any issues with the leaf blower and solve it.

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