8 Reasons your leaf blower won’t rev + how to fix

Typically, a leaf blower is a fundamental tool that is required for maintaining your compound or yard and keeping it clean at all times. However, to efficiently execute its task, a leaf blower depends on its internal engine.

The most common reasons why your leaf blower won’t rev are:

  • Insufficient Air Flow Into the Engine​
  • Insufficient Removal of Air From the Engine​
  • A Worn-out Spark Plug​
  • Clogged Carburetor
  • Compression Problems
  • Quality of Fuel
  • Primer not Pumped
  • Clogged Spark Arrestor
8 Reasons your leaf blower won't rev + how to fix 1

For the engine to run smoothly it must have air, spark, and fuel. The moment any of these three components are deficient or are not able to promote the capability of the engine, then the leaf blower will not rev.

Now let’s dive deeper into the reasons why a leaf blower won’t start or what undermines the functioning abilities of the leaf blower. Are you concerned that your leaf blower has refused to start? Do you want to know the reasons behind this? Don’t look too far. Not only will the rest of this article provide you with necessary answers but it will also show you ways by which you can avoid this problem or tackle it when it occurs.

Things to do When your Leaf Blower doesn’t Start

As said earlier, the leaf blower engine must have gas, compression, and spark so that it can start. If these components are absent, then the leaf blower will not start. To ensure that this does not happen, first, make sure that there’s fresh gas in the tank, because old gas after some time, accumulates water and burns poorly. If the fuel is old, replace it with a fresh one. Also, when you refill the tank, add a fuel stabilizer to the gas to help keep the fuel fresh. If you are sure that the fuel is fresh, carry out preventive maintenance on the air filter of your tool to ensure that the carburettor gets enough air to mix with the fuel to start the engine. You can follow the instructions in your owner’s manual on how to clean and properly maintain the air filter. For some leaf blower model, you will need to coat the air filter lightly with oil so that the right amount of clean air can freely enter the carburettor.

Now if the air filter is okay and functioning properly, then check the fuel lines for cracks. Usually, when fuel lines have cracks, the air enters the carburettor instead of the fuel. Certainly, the carburettor needs air through the filter to function, however, the carburettor does not need air flowing through the fuel lines. If you find cracks in the fuel lines, replace the fuel lines to avoid the improper flow of air. If the fuel lines are good but still the fuel doesn’t move through the lines when you press the primer bulb, then the fuel filter may be clogged and may need replacing. The fuel fillet should be replaced if it is covered with deposits as these deposits do not allow fuel to flow freely to the carburettor.

If fuel flows to the carburettor freely, try to pull the spark plug to check if the tip of the plug is wet. This will indicate that the cylinder is getting fuel. If the cylinder isn’t getting enough fuel because of the clogged carburettor jet, replace the carburettor, you may also want to rebuild it. When you pull out the spark plug but you notice deposits or corrosion on the electrode, then replace the spark plug with a new one.

Finally, check for compression. To do this, remove the spark plug and press your thumb over the opening, then pull the starter cord. When you do this, air should push from the cylinder. If you don’t feel the air pushing from the cylinder, then the piston rings probably need to be replaced. To get an accurate compression reading, you can use a compression gauge. Also, a damaged recoil starter can prevent your leaf blower engine from starting. If you are not able to pull the recoil starter rope, check the recoil starter to see if it is damaged. Replace it if needed.

Reasons why your leaf blower won’t rev

There are several reasons why your leaf blower won’t start and the earlier you can detect these problems the better. It is not unusual for a leaf blower to have problems starting especially after spending most of the year stored away in the shed, however, the good news about this is that, in many cases, the problem is not too severe and can be easily tackled. Here are some reasons why a leaf blower won’t rev.

1. Insufficient Air Flow Into the Engine​

For a good leaf blower to function efficiently, air must flow properly into the engine. If the air does not flow well, then the leaf blower will not start. Usually, the air filter is that part of the leaf blower that ensures air gets into the engine. Now when dirt and debris collect around or inside the air filter, the normal supply of air to the engine will become restricted. Hence engine failure will occur which will also render the leaf blower ineffective. To prevent these, make sure you clean the air filter to ensure the easy flow of air into the engine.

2. Insufficient Removal of Air From the Engine​

It is ideal for air to flow into the engine of a leaf blower, but it is also important that air is removed from it. Normally, the air is removed from the leaf blower engine through what is referred to as a muffler. The muffler often comes with a metal screen whose sole purpose is to inhibit the evasion of ignited residues. Often, the metal screen becomes clogged with particles of dirt and when this occurs, it becomes difficult for air to be removed from the engine. This problem is accompanied by a gradual buildup of carbon, which eventually causes the exhaust to be blocked. Hence, the leaf blower becomes deprived of its power because the engine will not start.

3. A Worn-out Spark Plug​

Another reason why a leaf blower fails to rev is because of its worn-out spark plug. Just like every other part, after a long period of usage, the durability of the spark plug might gradually deteriorate and become expired making it prone to damage. This can be visible when you begin to notice certain symptoms in your leaf blower spark plug, such as a damaged electrode, carbon build up around it, and a cracked insulator. If this occurs, then the spark plug needs replacement to put an end to the leaf blower problems.

4. Clogged Carburetor

This problem is one that often happens when old fuel is left in your leaf blower. If the fuel sits in the tank for too long, it becomes too thick and viscous, and if you try to use it like that, the viscous paste formed can block the carburettor, making it hard to start your leaf blower.

If this occurs, check the carburettor. You can either clean the carburettor (that is if the problem is not too serious), rebuild the carburettor (if the problem is a little serious) or replace the carburettor completely (in the worst-case scenario). However, to avoid this problem, always make sure that you never leave fuel sitting unused in your leaf blower for a long time.

5. Compression Problems

Often, your leaf blower may have little or no pressure coming into it. Now this lack of pressure can cause leaf blower hiccup or prevent it from starting. Usually, the pressure is a vital feature for a leaf blower to ensure that all the components are performing their activities in a similar manner. An inadequate amount of pressure can be indicated by leaks near the piston as well as the crankcase. The presence of leaks around the piston or crankcase can be taken as a clear indication of compression problems, and this problem will make it impossible for a leaf blower to rev or even function properly.

6. Quality of Fuel

It is important to know that the engine of your leaf blower always needs plenty of supply of quality fuel for it to function properly. And the fuel that is commonly used is gasoline. Now if the gasoline supplied is of poor quality, then the leaf blower will not start. A lot of people might be confused as to why fuel quality has become an issue. Truly, fuel can be stale, and stale fuel can prevent the engine from starting properly or even starting at all. In fact, for most leaf blowers that refuse to rev, this is a very common issue. If this is the problem you are facing with your leaf blower, then it is important for you to consider supplying the tank with fresh and quality fuel to replace the existing fuel which might have become stale.​

7. Primer not Pumped

When you want to start your gas leaf blower, you need to pump the primer before pulling the starter cord. If you don’t do this, there’s a great chance that you will have trouble starting it. So before you start the tool, always make sure to pump the primer about five times, then try pulling the cord again to know if this is the problem. Also, ensure to read the user manual to make sure you know how to start your leaf blower correctly.

8. Clogged Spark Arrestor

The spark arrestor of a leaf blower is a screen that is designed to prevent the leaf blower from emitting sparks. However, this part may become clogged with dirt, and if this happens, the machine won’t start. Always ensure to check the spark arrestor from time to time, remove it when dirty and clean it with a brush to resolve the problem.

How to fix the problem

1. Replace the leaf blower carburettor

As stated above, the leaf blower’s carburettor is responsible for mixing air and gasoline in the proper proportions to create a combustible gas. Now if the engine of your leaf blower starts and then sputters, or it doesn’t start at all due to lack of fuel, you may need to replace the carburettor. Usually, it is more cost-effective and quite practical to replace the carburettor instead of rebuilding it. Here are simple DIY steps on how to replace a carburettor.

  • Drain the fuel tank: First, ensure that you are in a well-ventilated area, then remove the fuel cap and empty the fuel from the fuel tank into a storage container that is approved and safe for use.
  • Disconnect the spark plug wire: To ensure that the leaf blower doesn’t start while you’re fixing it, disconnect the wire from the spark plug. This will prevent it from igniting suddenly during the repair process.
  • Remove the air filter cover: To do this, first, remove all the screws surrounding the air filter cover, then remove the air filter cover itself to expose the carburettor.
  • Remove the carburettor: First, remove the mounting screws around the carburettor. Then draw out the airbox and release it from the carburettor throttle and choke lever. It is important to take note of the configuration or arrangement of the small and large fuel lines on the carburettor so that you can easily reconnect them in the correct order later, and then remove the fuel lines from the carburettor.
  • Discard the damaged carburettor: Remove the carburettor mounting screws. Pull out the air box, and remove the fuel lines from the carburettor.
  • Install the new carburettor: Once you have removed the old carburettor, push the fuel lines onto the proper connections on the carburettor. Then insert the new carburettor into the airbox ensuring that the throttle and choke levers are positioned properly. Also, position the carburettor on the side of the engine and reinstall the mounting screws. Then reconnect the fuel lines and reinstall the carburettor mounting screws.
  • Reinstall the air filter cover: Place the air filter cover over the carburettor and secure it with the mounting screws that you previously removed. Make sure all screws are attached and secured properly.
  • Connect the spark plug: After replacing the carburettor, you can now reattach the spark plug wire that was removed earlier. Reattach the spark plug wire and start up the engine, your leaf blower should rev.

2. Replace the leaf blower fuel lines

The leaf blower’s fuel lines are responsible for carrying or transferring fuel from the fuel tank to the carburettor and from the primer bulb to the fuel system. However, after a while, the fuel lines become brittle and may even crack or break. If the fuel line is brittle or damaged, then you should replace it with new ones. But be careful enough to install the new fuel lines on the engine the same way the original fuel lines were placed. Here are steps on how to replace fuel lines.

  • Drain the fuel tank as practised in (1) above. Then disconnect the spark plug wire.
  • Remove the blower tube: to do this, loosen the thumbscrew on the front of the housing and pull the blower tube off. Remove the air filter cover.
  • Remove the carburettor as well as the fuel lines from the carburettor. Also remove the adapter screws, the carburettor adapter, and an air dam.
  • Next, remove the fuel tank.
  • Pull the fuel lines out of the tank. Remove the fuel filter from the end of the small fuel line, then pull the small fuel line out of the tank through the mounting hole. Once done, push the large fuel line into the tank through the mounting hole and pull it out of the mouth of the tank.
  • Next, install the large fuel line: cut one end of the large fuel line at any angle. Then push the end into the tank through the mounting hole. Make sure it is far enough so that you can grab the end with needle-nose pliers. Tug the opposite end of the large fuel line until the grommet touches the side of the tank. Install the grommet. Tug the fuel line to position the grommet.
  • Install the small fuel line: use the same method as the large fuel line.
  • Attach the fuel filter, then reinstall the left side of the housing. Set the left side of the housing to be near the leaf blower and place the fuel lines through the hole in the housing near the carburetor.
  • Make sure the handle is properly placed before pushing the housing back together. Position the thumbscrew in the housing in front of the blower and turn the screw just until it catches the nut but doesn’t tighten it yet. Install two other housing screws to secure the housing while you install the fan cover.
  • Snap the fan cover into the housing while holding the spring in the loaded position.
  • Insert all of the housing screws and tighten them firmly. Reinstall the guard cover as well as the fuel cap.
  • Reinstall the carburetor
  • Reinstall the blower tube by pushing it back on the front of the housing, then tighten the thumbscrew.
  • Finally, connect the spark plug to start the engine.


After replacing the necessary parts, your leaf blower should start. In conclusion, all the above issues are some of the common reasons why a blower won’t rev, and It is not easy to detect some of the issues in a leaf blower alone. To properly diagnosis problems, contact an expert to know the exact issue and tackle it. We hope this article has been helpful. Good luck!

Recent Posts