17 Causes Your Briggs & Stratton Lawn Mower Won’t Turn Over

Mowers from several different manufacturers, such as Toro, Craftsman, Yards Machines, and Cub Cadet, employ tiny engines manufactured by Briggs & Stratton.

If your mower starts acting up and won’t start, investigate the cause of the disruption in the flow of air, gasoline, and spark to the engine.

Possible causes of a non-starting Briggs & Stratton lawnmower engine include: a faulty safety switch, old gas, a clogged fuel filter, a dirty carburetor, a stopped fuel line, and a clogged air filter.

The electric start on your riding or push mower made by Briggs & Stratton could be malfunctioning due to a dead battery, damaged or loosened connections, or a broken ignition switch.

Before doing any repairs, it is imperative to take the necessary precautions, such as removing the spark plug boot(s).

17 Causes Your Briggs & Stratton Lawn Mower Won't Turn Over

Trouble Starting Your Briggs & Stratton Lawn Mower

Your Briggs & Stratton Outboard Motor’s Gas Tank Is Empty

Your Briggs and Stratton lawn mower won’t work if you run out of gas. I just bring it up in case you didn’t think to check the gasoline level when you first started trying to figure out why your car wouldn’t start.

You could have a defective fuel gauge or a fuel leak if you’re using more gas than usual.

The solution is to use new, 87-octanes-or-higher unleaded gasoline to refill the tank. Pick a fuel with an ethanol content of no more than 10%.

Currently available lawnmowers from Briggs & Stratton are powered by 4-cycle engines that run on unleaded fuel.

If you have an older mower powered by a Briggs & Stratton engine, it may be a 2-cycle model that operates best when fed a gas and oil mixture. There will be only one fueling port on a 2-cycle engine that can take a combination of gas and oil.

Old or Corrupt Fuel in Your Briggs & Stratton Lawnmower

Around the 30-day mark, gas starts to degrade, break down, and become less effective. Ethanol, which is present in gasoline, is a moisture magnet.

After the moisture evaporates, a sticky residue is left behind that might block your fuel system. This includes the fuel lines, the filter, and the carburetor.

You must buy gas from a busy gas station and utilize it within 30 days.

If you won’t be using the fuel up within that time frame, you should stabilize it with an additive to extend its shelf life. Take a look here to learn more about the benefits of Sea Foam.

A fuel siphon pump can be used to drain the used fuel from the tank. Refuel the vehicle and use a fuel additive to flush the fuel system and eliminate moisture.

In my opinion, Sea Foam Motor Treatment is the best product for treating vehicles. Another excellent product is STA-BIL.

Once the mower is started, let the engine run for a bit so the treated fuel mixture can circulate through the fuel system.

Briggs & Stratton Lawnmower with a Defective Fuel Cap

A vent is built into your gas cap. If you forget to unplug this vent, the gasoline tank will generate a vacuum, starving your Briggs & Stratton lawnmower’s carburetor of the fuel it needs to run.

The gas cap could be the problem, so try starting the mower without it. If the previously non-starting Briggs & Stratton now fires up, you can reinstall the cap while the lawnmower is in operation.

Hopefully the mower will splutter and die from lack of gas soon. If that’s the case, try taking off the cap and starting the mower again.

If your Briggs & Stratton dies after starting after the fuel cap has been removed and reinstalled, the problem lies with the fuel cap.

A NEW gasoline cap is the answer. You can get one at a local Briggs & Stratton dealer, or you may order one from Amazon.

Faulty Spark Plugs, Loose Connections

It’s also possible that a damaged spark plug or a loose connection at the plug is the cause of your Briggs & Stratton’s inability to start. The engine may refuse to start if the spark plug has carbon buildup or oil on the tip.

Verify a solid connection at the spark plug by testing the wire. It is imperative that you gap your spark plugs according to the engine manufacturer’s guidelines.

A spark plug wire that is loosened or a spark plug that is not properly gapped might cause starting and running issues.

Removing the spark plug and checking it for carbon buildup, broken porcelain, or burned electrodes is the solution.

Spark plug replacement (s). Use a feeler gauge to check the gap between the spark plug’s electrodes.

Ignition Coil Problems on a Briggs & Stratton Lawnmower

Ignition coils are what supply power to spark plugs, allowing them to ignite and kick-start an engine. If the spark plug doesn’t ignite, the engine won’t turn over.

After making sure the spark plug is fine, check the ignition coil’s continuity. A broken continuity indicates that the ignition coil has to be replaced.

Briggs & Stratton Mower with Clogged Air Filter

To function, the air intake of your Briggs & Stratton must be kept open. Dirty air filters prevent air from reaching the engine, which can cause it to overheat. If the air intake on a Briggs & Stratton engine is blocked, the motor will not turn over.

For the engine to keep going when the air intake is restricted by the air filter, it must locate an alternate source of air. If it starts to overheat, it may pull air from the crankcase to cool down, which can severely harm the engine.

REMEDY: Replace a clogged air filter. If the filter appears to be severely clogged or broken, you should consider replacing it. To clean the air filter on a Briggs & Stratton, please refer to the guidelines below.

Read the instructions that came with your filter to learn how to clean it properly.

In order to clean the PAPER air filter of a Briggs & Stratton engine, you should:

  • Get rid of the protective cover of the air filter.
  • Take out the air purifier.
  • Use a clean, dry cloth to wipe away any dust or debris from the air filter housing and the air filter cover. Take cautious not to let any dirt enter the air intake.
  • To remove dust and debris from the air filter element, tap it against a hard surface.
  • To use, simply place the filter in front of the light. You can keep using the filter as long as you can still see clearly through the paper. A new filter should be used if the old one is no longer effective at letting in sufficient light or when it has been damaged.
  • Put in a fresh filter or clean the one you have.
  • Replace the air filter cover.

To cleanse a Briggs & Stratton FOAM air filter, you should:

  • Get rid of the protective cover of the air filter.
  • Take out the air purifier.
  • Use a clean, dry cloth to wipe away any dust or debris from the air filter housing and the air filter cover. Take cautious not to let any dirt enter the air intake.
  • Check for broken parts in the air filter. It has to be replaced if it has become particularly dark in color, is brittle, or has tears. If the filter is still functioning well after cleaning, use it.
  • Foam filters can be cleaned by washing them in water and mild detergent to get rid of oil and grime.
    It’s important to thoroughly clean the filter. To drain the filter, give it a good squeeze. If you want to keep the filter in good condition, avoid wringing it.
  • Please let the filter air dry.
  • Cover the filter entirely with clean engine oil. Drain the filter of any surplus oil. Foam pre-filters should never have oil applied to them.
  • Wrapping another filter around the paper filter element creates what is known as a pre-filter. The paper filter may be harmed by this.
  • Put the filter in place.
  • Replace the air filter cover.

Briggs & Stratton Mower: A Faulty Fuel Pump

For the carburetor to function, a fuel pump must be installed. The only time you’ll see a fuel pump on a Briggs and Stratton engine is if the carburetor is mounted higher than the tank.

The gasoline pump, like any other mechanical component, might wear down and stop working eventually. The pump parts may have deteriorated over time due to the usage of outdated fuel.

To diagnose a faulty fuel pump, check for fractures in the vacuum fuel pump. Cracks in the fuel pump or fuel leaking outside of it indicate that the pump is no longer receiving fuel under pressure from the crankcase and delivering it to the carburetor.

If your mower has a fuel shut-off valve, you can use that, or you can use clamps to start and stop the fuel flow. To ensure gas is reaching the pumps, the flow must be intermittently stopped and started.

If fuel is not moving freely to the pump, perhaps there is a blockage in the fuel line or fuel filter.

Once you’ve established that gasoline is reaching the pump, you can tell if it’s working properly by observing whether the fuel is flowing steadily or pulsating as it leaves the pump.

To do this, disconnect the gasoline line from the carburetor and turn off the fuel pump. Put the line somewhere convenient. Start the gas and the mower.

Keep an eye on how much gas enters the tank. Good fuel flow, whether steady or pulsing, indicates a healthy fuel pump. If it does not, then you need to get a new gasoline pump.

Briggs & Stratton Lawnmower’s Clogged Fuel Filter

The gasoline filter acts as a first line of defense, filtering the fuel to remove any contaminants before they enter the engine. Make certain that the same amount of fuel is flowing out of the filter as is being pumped into it.

If it doesn’t, it’s probably plugged and the Briggs & Stratton won’t start until you replace it.

If you find that gasoline flow stops at the filter, you need to substitute it. If your Briggs & Stratton needs a new fuel filter, you should get one. When installing the filter, make sure the arrow is pointing in the direction of fuel flow.

Briggs & Stratton Lawnmower with a Blocked Fuel Line

The fuel line of your Briggs & Stratton lawnmower can become clogged with debris and old fuel.

Remove the gasoline line, spray the tube with carburetor cleaner, then blast compressed air through it to cleanse it. A new gasoline line is an alternative option.

Carburetor of a Briggs & Stratton Mower Is Clogged and Dirty

The carburetor is a device that mixes fuel and air in the correct proportions for combustion in an internal combustion engine. When you use old ethanol-containing fuel, your carburetor can have crusty buildup and sticky deposits.

Failure of the carburetor to properly control the ratio of gasoline to air will cause your Briggs & Stratton engine to sputter or refuse to start.

If you’re mechanically inclined, you can try cleaning the carburetor on your own; otherwise, take it to a lawn mower repair business. Here you will find instructions on how to maintain your Briggs & Stratton carburetor.

If the carburetor looks like it’s in horrible shape, you might want to consider getting a new one.

Incorrectly Working Safety Switch on a Briggs & Stratton Lawnmower

The operator presence control system of your lawn mower may consist of more than one safety switch. When the rider gets off of their seat, the engine will automatically shut off.

When the safety bail control bar is not pushed into the handle, the mower cannot be started.

It’s possible that the switch is broken on your Briggs & Stratton mower, making it inoperable.

The riding mower’s brake switch is another important safety feature to examine.

The problem can be solved by temporarily disabling the safety switch. For your own protection, never run a mower without the safety switch in place.

Make sure that all of the safety switches on the machinery you use are functional at all times. It’s time to switch out that faulty switch.

Briggs & Stratton Engine with Loose or Corroded Cables, Wiring, and Terminals

Verify that the terminals and cables of your riding mower or electric-start push mower are free of corrosion. Then, check for any disconnected wires or cables that could be the cause of the problem.

Locate the solenoid and starter by following the cables leading from the positive battery terminal. Mower starting issues might arise from loose or corroded cables.

If your Briggs & Stratton lawnmower is still giving you trouble, make sure you have checked all of the wiring and components.

Fix: check sure all wiring is firmly secured to the mower parts and tighten the wires. In order to get rid of corrosion, combine baking soda with water.

Always start with the negative cable and work your way to the positive when disconnecting a battery.

Briggs & Stratton Mower With a Weak or Bad Battery

A fully charged battery is necessary for starting your Briggs & Stratton lawn mower. If the battery is low, it will need to be charged before it can be used.

SOLUTION: Use a multimeter to check your battery. For a 12-volt lawn mower battery, you’ll need a reading of around 12.7 volts. If the battery level is below this, you should charge it.

You should get a new battery if your old one doesn’t keep its charge.

Briggs & Stratton Lawnmower Ignition Switch Failure

You put the key in the ignition and turn it, but the car doesn’t start. The starter won’t turn on your Briggs & Stratton lawn mower. One possible cause is the car’s ignition switch. An ignition switch test can be performed with a multimeter.

If the switch is broken, simply substitute it.

Solenoid Failure in Briggs & Stratton Lawnmower

A solenoid on a Briggs & Stratton lawnmower is an electromagnetic switch that acts as an on/off button, activating the starter motor and allowing the engine to turn over. If you hear a click or hum whenever you turn the key, it’s time to inspect the solenoid.

When a wire leading to your Briggs & Stratton mower solenoid gets too hot and smokes or melts, this could be another sign that your solenoid is malfunctioning.

If the solenoid is faulty, you should replace it.

Briggs & Stratton Lawnmower with a Bad Charging System

Even while the charging mechanism isn’t the primary¬†cause of a non-starting riding Briggs & Stratton mower, it might contribute to a weak battery.

When the battery isn’t fully charged, the mower won’t start. This might happen if the charging system malfunctions.

It’s possible that the issue is a faulty stator or alternator, or any one of a number of other electrical components. If you have an ohm meter and want to see how well your charging system is doing, read this page.

If you think the issue may be related to the charging system, the best course of action is to have a small engine technician inspect the system and determine where the issue lies.

It might get pricey trying to fix your mower by guessing what’s wrong and replacing expensive parts.

Misuse of a Briggs & Stratton Lawnmower

If you don’t follow the correct starting steps, your Briggs & Stratton mower won’t start.

If you want to avoid activating the safety measures that disable or refuse to start your Briggs & Stratton lawnmower, consult the instructions that came with your machine.

On a riding mower manufactured by Briggs & Stratton, for instance, the engine won’t start unless the brake is applied and the PTO switch is in the off position.