Why does a lawn mower engine backfire

Sometimes after running your mower for some time, the air filter can become blocked with all kinds of debris like crud, grass clippings or paint chips.

The air filter in a lawn mower acts to prevent these particles from entering the engine as a first line of defence. Once it becomes clogged, you may experience strange engine sounds, a misfiring engine, reduced fuel efficiency or even black smoke from the exhaust.

Over time your spark plug will accumulate wear and tear. A failing spark plug is one that is unable to produce enough current to spark the fuel. Sometimes it can become chipped or black and carbonated over time. A worn or damaged spark plug can the engine to stall or have poor fuel economy. The fuel filter screens out dirt and debris from entering the fuel. Old fuel can clog up the fuel filter which may prevent it from effectively filtering out any impurities.

Incorrect fuel maybe preventing the proper function of your engine by clogging up essential components. You might also want to check that there is no water contaminating your fuel. A good way to do this is to take off the float bowl to take a look inside. You may see tiny droplets of water in the bottom and if this is the case, you need to drain the fuel out and replace it.

Your carburetor is responsible for creating the right fuel to air mixture in order for complete combustion to take place. Sometimes, the residue from old fuel can create problems in the carburetor. If you continue having problems with your lawn mower backfiring at shut off then there are special pieces of equipment known as anti after fire solenoids which can be used to prevent the problem in future.

However, this is not something that the average homeowner can fit on their own and it is important that you take your lawnmower to a professional to have these fitted. Once installed, this feature will mean that you no longer have to idle the mower after use and before shutting off. This can make the mowing experience a lot more convenient. Gas-powered lawn mowers are very effective and powerful tools that can make light work of mowing your grass , especially if you have a larger garden.

However, they are not without their problems and one of the most common is that a lawn mower will backfire at any point during operation. There are several causes for this but for the most part, they are easily fixed either at home or by taking the mower to a professional repairs person.

Check out our article on how to align mower blades. Your email address will not be published. Keeping your garden well maintained involves much more than just trimming the lawn and tidying up.

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Just so you know, we may collect a share of sales or other compensation from the links on this page. Thank you if you use our links, we really appreciate it! Table of Contents. Riding and Push Mowers. Common Issues. Fuel-Related Issues.

How to Fix Fuel-Related Issues. Engine Related Issues. Combustions of fuel anywhere in the engine other than the combustion chambers or in the exhaust will always produce a bang or backfire. Engine backfires are caused by basic and simple chemical malfunctions, and solving the backfiring problem is not difficult.

It is necessary to fix the issue as soon as possible so that the engine and exhaust are not damaged beyond repair. Information about engine backfiring in lawnmowers presented in this article will surely help you manage a backfiring situation in a better way. This production of power takes place in either 2 strokes or 4 strokes. In both cases, combustion of the air-fuel mixture is the most vital stroke in which a spark ignites the mixture, causing an explosion and, therefore, a release of energy.

Combustion of fuel takes place in a controlled manner inside the combustion chamber. Combustion or burning of fuel anywhere else will cause a bang, which is called backfire. Backfiring in lawnmower engines can be caused by either fuel-related causes or engine related causes.

Both are explained below. Just like any burning, fuel combustion requires oxygen. Each engine is designed so that the correct air-fuel mixture is provided to the combustion chamber during operation. All strokes are timed perfectly for the complete combustion of fuel, maximum energy release, and smooth machine operation. If the air-fuel mixture is in an incorrect proportion, it will cause all sorts of problems for the engine.

For example, if the fuel is too rich, it could result in your engine blowing smoke. The timing of all processes in the combustion chamber is vital. A process happening early or getting delayed even by some seconds can cause problems.

An incorrectly proportioned air-fuel mixture can cause a timing disruption. If there is too much air in the combustion chamber, the engine will not create a spark with enough power to ignite the fuel for some seconds.

Why is my Briggs and Stratton backfiring? Why is my Briggs And Stratton engine backfiring so much? Carbon buildup and or lean running condition. Carbon particles become redhot and ignite fuel that is sucked into the cylinder after the ignition is turned off. If it runs lean, the exhaust valve can get red hot and do the same thing. Can a lawn mower explode? Lawn mowers can explode as a result of catching fire or unauthorized changes and modding of the engine and the fuel system.

Under normal use, chances of a lawn mower exploding are very low, but this can be further prevented by regular maintenance and service. How do I make my engine backfire? Hit the gas to the floor, then lift it up, keep the rpm around , but repeatedly floor the pedal.

If you're lucky you'll get fuel passing through the engine without igniting, once it reaches the hot exhaust you'll get a backfire. How do you adjust the governor on a small engine? To adjust the governor, you would loosen the screw on the bottom of the governor arm and push the governor arm so the throttle is wide open.