You’re relaxing, reading a book, and about to take an afternoon nap after a busy week. Suddenly your next-door neighbor’s leaf blower breaks the blissful silence! It’s at this point where you ask yourself who would have invented such a device? I can’t tell you who it was as there seem to be multiple contenders, but the consensus seems to be that 1959 saw the release of the household blower.

Leaf blowers, like all mechanical devices with moving parts, will wear over time and with use. Like any machine, it will require regular maintenance to keep it running reliably. 

Like your lawnmower, especially if you use one with a gas engine, you’ll need to service the motor from time to time. Leaf blowers are generally very reliable, but they are prone to overheat occasionally. Let’s look at some reasons why this happens and what to do about it.

Leaf blowers are available in electric and gasoline-operated models.  

Primary Parts of a Leaf Blower

• Powerhead (houses the engine or motor)
• Impeller (Nylon or metal fan)
• Blower tube

Possible Reasons That A Leaf Blower Overheats And How To Fix Them

1. Airflow Restriction

Let’s look at the engine and blower section separately and how they affect each other.

A gas-powered leaf blower has an engine, and engines generate heat. 

The engine’s purpose is to drive the impeller or fan, which creates the jet of air that is forced down a tube where it exits to blow the leaves out of its way.  

The engine relies on the air entering the inlet for the temperature to remain within its operating range. As such, it is vitally important that the airflow to the engine is not hindered. In better models, the motor will turn itself off to cool down if the temperature rises too high.  I cheaper models, the engine will keep running until something melts or breaks. 

The blower section housing the impeller is linked to the engine. The engine drives the fan, which sucks air into the fan and expels it at high speed and pressure. For the impeller to work effectively, it needs air. As such, the air inlet or inlets need to be free of any obstruction. 

Should the impeller inlet be blocked or the flow of air be severely restricted, the output airflow of the tube will be low. To increase the flow rate, the operator may, in most instances, over-rev the engine to get the required result. This will, in turn, at the very least cause the engine to overheat.

Electrically powered leaf blowers use the same operating principles as gas engine-driven models. The Electric motor drives the impeller or fan, which then blows the air down a tube under pressure and high speed. The expelled air is then used to blow away leaves and other loose debris.

Overheating of the electric motor can happen in the same fashion as with a gas engine as 

Sufficient airflow is required to keep the electric motor within operating temperature.  

2. Dirty Impeller

The impeller plays a vital role in the ability of the leaf blower to perform the task for which it was designed. An impeller is basically a fan that sucks air in and then expels it under pressure. The impeller consists of blades that spin at thousands of revolutions every minute and suck in and expel a lot of air. 

Along with the air that is being sucked in comes debris and other airborne particles. These particles can build up on the impeller over time, particularly if they contain an adhesive component, e.g., sawdust particles.

Should the buildup be excessive on the impeller, the efficiency of the part will be negatively affected, which can severely affect its functionality. This may result in the engine being over-revved to generate the airflow desired, causing the engine to overheat. 

What To Do:

If you find that you are revving the engine of your leaf blower excessively to get the desired speed, switch the leaf blower off and do a thorough check that an excessive buildup of dirt is not slowing down any of the parts, including the impeller. 

3. Damaged Impeller

Similarly, a damaged impeller’s ability to function as designed will negatively affect the leaf blower’s ability to run smoothly. If any piece of the impeller has broken off, a vibration will be felt as the impeller or blade will be unbalanced. Should the impeller have dislodged from the driveshaft, no vibration may be felt, but, there definitely won’t be any air being blown out of the tube. 

The danger here is that the operator will over-rev the engine in an effort to generate the required airflow, which will eventually cause the engine to overheat.

What To Do:

If you feel the leaf blower vibrating excessively while using it, switch it off and check if the impeller is cracked or broken. If no air at all is coming out of your leaf blower, check that the impeller has not become dislodged. 

4. Engine Air Filter

All gas engine leaf blowers have a carburetor. The purpose of this device is to mix the air with the fuel as both pass through the carburetor. An air filter located at the carb’s inlet filters the air that is sucked into the engine. The environment in which one operates a leaf blower are often not ideal. Dust is constantly being sucked into the air filter.  

Should the air filter not be regularly cleaned or replaced, the air filter will gradually become increasingly less efficient or, in other words, it becomes more and more blocked. 

As the air filter’s effectiveness is reduced and therefore reducing the available air reaching the carburetor, the fuel and air mixture is negatively affected. Reducing the available airflow will increase the fuel being fed into the cylinder. The fuel mixture imbalance will raise the cylinder’s temperature, which will cause the engine to run hot and eventually overheat.

What To Do:

Clean or replace the air filter regularly. A leaf blower that cannot suck air in is not able to blow it out effectively.

5. Two-Stroke Fuel Mixture

Most gas engine-driven leaf blowers are fitted with two-stroke engines that use a fuel and oil mixture that must be mixed before the fuel is poured into the gas tank. The two-stroke oil must be mixed with the fuel at a specific ratio, e.g., 25 to 1 or 50 to 1. The required mixing ratio will be indicated on the blower itself, usually on or near the fuel cap of the blower.   

Never attempt to run a two-stroke leaf blower’s engine without adding the two-stroke oil. The purpose of the oil, which is added to the fuel, is to lubricate the cylinder as the fuel is squirted into the combustion chamber. Failing to add the two-stroke oil to your fuel at the correct ratio will result in the piston running dry and overheating, which in turn can lead to engine failure and permanent damage.  

What To Do:

Always carefully check the exact mixing ratio of fuel to two-stroke oil. Never try to operate your leaf blower without using the correct mixture.

6. Storage Of Your Leaf Blower

Given that leaf blowers are generally not in use all year round and spend a fair portion of the year in storage, chances are high that a homeless rodent, or insect, may well have made your leaf blower into its perfect home.

When placing your leaf blower in storage, it is good practice to clean all the major components and replace any worn parts so that the blower is ready to use when next needed. Leaving a buildup of grime, oil residue, crass and leaf clippings, sand and such, is not good practice. Given time, the debris will dry into a hard layer, making cleaning it much harder in the future. 

Hidden debris may well become the reason for the leaf blower overheating in the future.  Removal of the main covers may be necessary to ensure all the hard-to-reach spaces are accessible.

Thoroughly cleaning the filters is one of the most important areas to focus your efforts.

What To Do:

After its long Winter, Spring, and Summer break, I recommend giving the leaf blower a good check-over and service before putting it back into service. Check the inlet and general ventilation ports carefully for any obstructions to avoid the leaf blower overheating due to a blocked airway.

7. Clothing Obstructing the Air Intake

A loose Item of clothing could foreseeably create a problem. Imagine a crisp Fall morning, and you’re dressed to keep the cold out. The leaf blower is running, and you’re wearing ear protection which effectively reduces the noise of the machine and its engine. Engrossed in the task at hand, you don’t notice that the loose end of your scarf has been sucked onto the engine’s air inlet and is blocking the cooling airflow to the engine. The machine eventually grinds to a halt from overheating, and the damage is done. 

What To Do:  

Always ensure that you are not wearing any loose clothing items that could affect the workings of a leaf blower, as it may also place the operator in danger.

8. Engine Lubricants 

Engine lubricants play a vital role in protecting the internal moving parts of any engine. Leaf blowers use either a four-stroke (4-cycle) or two-stroke (2-cycle) engine. The four-stroke engine uses pure gasoline, where the two-stroke requires two-stroke oil to be mixed into the gas to lubricate the piston during operation.

Both engines have an oil sump of some type that houses the oil that lubricates the engine’s moving parts. These oil levels need to be checked regularly to ensure the oil is sufficient to ensure the engine doesn’t run dry. When this happens, the bearings within the engine overheat and self-destruct, causing the machine to be unusable. 

Using the specified oils as required for your specific brand of leaf blower cannot be emphasized enough. Two-stroke engines generally operate at much higher revolutions than a four-stroke. This means that the moving parts within the engine operate at extremely high speeds and endure significant forces. Using the incorrect oil in the engine will not lubricate the parts as it should and will cause wear and heat buildup.  

What To Do: 

All oils degrade over time with use. Therefore, it is good practice to replace the oils when they start changing color. Generally, the oil will start turning black due to heat exposure, and microscopic metal particles shed from the moving parts over time that mix with the oil. Fresh oil prolongs the life of the leaf blower engine and allows the engine to run at low operating temperatures. 

9. Regularly Check Engine Coolant Levels 

Most, but not all, engines have a radiator that assists in keeping the temperature of the engine down. Regular checks by the leaf blower operator are required to ensure that there is sufficient water in the radiator for the cooling process to be effective. The reliance on the radiator for cooling the engine is so high that if the radiator water levels drop too low, this can cause the engine to overheat and fail. 

What To Do:

Before you start your leaf blower, always check that there is enough water in the radiator.

10. Ambient Temperature

The outside temperature, or ambient temperature, should generally not be a factor to consider unless you operate your leaf blower in a very hot area. It is realistic to expect a leaf blower operated in a cool climate to outlast one regularly used in Arizona or the Mojave Desert.

Running your leaf blower on sweltering days will definitely increase the risk of the engine running hotter than it normally would. This temperature difference may even push the leaf blower temperature over what it was designed for, especially if used for a prolonged period. In the worst-case scenario, the leaf blower engine could well overheat.    

What To Do:

If possible, do not operate your leaf blower for long periods if the ambient air temperature is extremely high. Wait until later in the afternoon when the air is cooler.

Conclusion

Virtually all the leaf blower overheating issues are caused by airflow problems. The operating conditions associated with using a leaf blower are seldom ideal because dust and grime are getting blown up everywhere. As such, regular maintenance and cleaning of all the air filters and air inlet channels is vital to ensure that your leaf blower gives you years of trouble-free service.