What are the reasons for Snowblower’s Backfiring?

Why do Snowblowers Backfire

The beginning of winter marks the start of the snowy season, with temperatures dropping below freezing in many places. As a result, we often have to bring out the snowblower to clear it out. These machines help clear the snow quickly and effectively, helping you gain access to your front porch and lawn. 

However, I bring out my snowblower but I had some difficulty in starting it, the snowblower started backfiring. It started making an unpleasant loud bang, and I don’t know why this is happening so I started doing some research about Why do snowblowers backfire?

Snowblowers backfire when the fuel mix combusts outside of its engine, causing a loud and uncontained bang. A backfire commonly occurs when your engine is slowing down or shutting off. This can happen due to engine timing issues, the fuel gas is too old or the spark plugs have gone bad. 

When the combustion process within the cylinders of the engine is incomplete, it can result in some fuel being sent out through the exhaust port into the muffler. If your muffler is hot enough, it can provide the temperature needed to cause ignition within. This resulting bang is what is commonly known as a backfire.

Engines have to be timed correctly so that the ignition spark occurs at the optimum moment just after the by-products have left the exhaust. Delayed timing can lead to the ignition process starting before the exhaust valve has allowed the by-products out. 

As a result, your engine will have some unburnt fuel left outside of the combustion chamber, causing it to backfire.

Another reason why your engine could backfire is because of spark plugs gone bad. The spark plug is responsible for providing the electric spark at very high temperatures that will ignite the fuel mix. 

If your spark plugs are worn out or fouled, then they will not be able to ignite the mix properly, affecting the timing and efficiency of the engine. This could eventually lead to an engine backfire.

— Also read: Can you use a Leaf Blower for Snow Removal as a Snow Blower do?

Read on as I discuss a few other queries regarding snow blowers and the issue of backfiring based on my previous experiences. This includes the reasons why a snowblower can backfire, the possible consequences, and if damages the engine in any way. 

I hope that after reading this article, you will have the knowledge needed to understand what the reasons are for your engine backfiring and resolve the problem quickly.

What causes snowblower to backfire?

Fuel sitting in the tank over storage is one reason why a backfire occurs. Other reasons include damage to your muffler as well as lean carburetor adjustment. If you decelerate the speed of the engine too quickly, then you also increase the chances of having your engine backfire.

  • If fuel is not treated for storage using additives and stabilizers, it will lose its volatility and lose its ability to flow. This will clog the fuel supply system, thus preventing fuel to flow to the engine. As a result, the engine will not have a proper mix of fuel and air, causing it to backfire.
  • The muffler and exhaust system is critical for an engine to function properly. If the muffler is poorly designed or has issues, it can cause improper evacuation of the hot by-products of the combustion process. As a result, there may be some unburnt fuel left in the engine, which can eventually lead to a backfire. 
  • A carburetor controls the amount of fuel to air ratio in the fuel mix which is to be combusted. If your carburetor is set to run too lean, then the amount of fuel in the mix is too little. This will lead to improper conditions for combustion, causing the engine to backfire.
  • The last reason why a snowblower may backfire is because of the user input. Small engines like these are not as rugged as automobile engines. 

When you decelerate the engine too quickly, there is a high chance that combustion will be incomplete due to a sudden increase in the amount of air intake, causing your fuel mix to become lean. This will result in unburnt fuel entering the exhaust, which may eventually ignite and cause backfires.

What does it mean when your snowblower backfires?

If your snowblower has backfired, it means that you are running on old gasoline that is not fit to be used anymore. If not, then the engine tuning is done such that your fuel mix is too lean. It could also mean possible damage to your muffler, as well as worn out spark plugs.

A common reason why snowblowers backfire is because of old gasoline that has not been stabilized before being stored. It can degrade over this period, leading to gunk and dirt mixing within the gas. 

Most manufacturers tune the engine of your snowblower to allow it to run with a healthy fuel to air ratio. If you have tweaked your engine for better fuel efficiency, there is a chance that the fuel mix is too lean. If you have made the fuel mix too rich for improved performance, then there is a high chance that there is unburnt fuel in the engine after combustion, which could also result in a backfire. 

A hole in your muffler can result in exhaust gases slipping out earlier than supposed to. This can result in a backfire if the gases are still hot and contain some fuel. 

If your spark plugs are worn out, you will experience a backfire along with reduced engine efficiency and stuttering. This is because the electrode is not able to provide the required spark at the precise moment when the fuel-air mix is correct, resulting in incomplete combustion.

Do read on as I also give you tips on how to tackle these problems to ensure you can eliminate engine backfire in the future.

How do you fix a backfire on a snowblower?

If your gas has remained within the tank for long, change it. Adjust the carburetor settings or clean it properly, because snowblowers don’t use oil filters and small dust particles can block the engine pipes easily. Check the muffler for possible damage and punctures. Check your spark plug for loose connections and dirt accumulation.

Gasoline stored in a fuel tank can go bad over extended periods of storage. If this is the problem, drain the fuel tank and add fresh gas to it. Allow your engine to idle for some time so that the new gas flows through the entire fuel system, helping get rid of the gunk that may block the flow through it. You could also try using fuel with low or no alcohol content in them to see if it resolves your backfiring issue.

Depending on how your current mixture of gas is, adjust the carburetor settings. If your mixture is too lean, adjust the carburetor to reduce the flow of air into the engine. To ensure that your mixture is not running too rich, set your carburetor to allow increased airflow.

A muffler might get damaged or punctured due to an accident or wear and tear. As a result, it will lead to the improper outlet of gases, causing your engine to backfire. After thoroughly inspecting your muffler for such a problem, try to fix it or replace it altogether depending on the severity of the issue.

Check your spark plugs and the connecting wire to ensure there is no loose connection. If that’s the problem, push the wire back into the spark plug socket. If you have fouled tips, clean them properly to help them efficiently ignite the fuel mix. 

However, if the electrode of your plug is almost worn out completely, you will have to replace the spark plugs altogether for a permanent fix.

If you don’t want to face this problem next winter, then make sure to do basic maintenance before you start your blower for the work, you can watch this detailed video of how you can do the basic maintenance at home easily.

Does a backfire damage an engine?

No, a backfire does not damage an engine. However, backfires can cause damage to the exhaust and intake outlets in your snowblower. But if you don’t check and repair this backfiring of your engine, then it can add up to a big problem in the future, so it is better to solve it as you find your engine is showing the problem.

Backfires occur outside of the cylinders of the engine, where the combustion is supposed to take place. As a result, no damage occurs to it. However, you will experience a loss of power and forward motion as soon as your engine backfires.

A backfire however can severely damage your intake and exhaust ports, especially the muffler. These components are not designed to withstand explosions that an engine cylinder can handle. This can cause improper functioning of these components.

While intake ports can get clogged with debris from the damage, the muffler can have internal damage that prevents the effective escape of by-products from the engine. In some severe cases, it can also punch a hole through your muffler system, which is dangerous.

Another drawback of having a backfire is that your engine’s power output is decreased drastically. It also results in very poor fuel efficiency, as your engine will consume more fuel than required while in operation. This will lead to increased expenditure when it comes to purchasing gasoline for your snowblower.

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