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14 Reasons Your Bad Boy Mower Won’t Start: SOLVED!

It is so frustrating when your lawn mower won’t start. It becomes increasingly frustrating once you realize there are so many things that can cause a starting problem. It’s tough to know just where to begin so I put together this list to help you troubleshoot your problem.

A Bad Boy lawn mower will not start when it is not getting air, fuel or spark. This is often caused by a plugged filter, bad fuel, dirty carburetor, plugged fuel components, bad spark plug, faulty electrical components or faulty charging system.

Keep reading for a complete list of items affecting your starting issue along with tips to repair a gas-powered Bad Boy lawn mower. If you own a Bad Boy diesel lawn mower and are have starting issues, check out my guide: Reasons a Diesel Lawn Mower Won’t Start.

Bad Boy Mower Won't Start - Dirty Air Filter

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Follow all safety instructions provided in your equipment operator’s manual prior to diagnosing, repairing or operating. Consult a professional if you don’t have the skills, knowledge or are not in the condition to perform the repair safely.

Reasons Your Bad Boy Mower Has a Starting Problem

Bad Boy Fuel Tank is Empty

We all know a Bad Boy mowers require fuel to run. Sometimes, during the heat of the moment, you forget to check this obvious reason. It could simple be you forgot to add fuel, but you may have also developed a fuel leak.  

Solution: Check for a fuel leak and repair. You can find more information on finding a fuel leak on your Bad Boy mower here. Add fresh fuel to your empty gas tank.

Old Fuel in Your Bad Boy Mower

Gas for a Bad Boy Lawn Mower

Most of the mowers Bad Boy offers in their lineup are gas-powered mowers. Gas that has been sitting in your mower for extended periods of time can breakdown and become less effective.

Gas can begin to breakdown as soon as 30 days after purchase causing running and clogging problems in the mower that can prevent your mower from starting.

Bad Boy gas-powered lawn mowers require an unleaded gasoline with a minimum octane rating of 87 and a maximum ethanol level of 10 percent. Ethanol, an environmentally friendly fuel, found in most gasolines today can have harmful effects on your Bad Boy mower’s small engine.

Ethanol attracts moisture. Overtime, this solution will separate from gasoline and sink to the bottom of the tank. When this solution evaporates, it leaves behind a gummy solution that can clog the fuel system. It can also corrode the fuel system and run hot causing engine damage.

Read more about the right gas to use in your Bad Boy mower here. I share more about the effects of ethanol along with best practices to store fuel.

Use Fresh Fuel in a Bad Boy Mower

Only use fresh fuel in your Bad Boy lawn mower. If you are unable to use your fuel within 30 days, add a fuel additive like Sea Foam to your fuel to stabilize it and reduce moisture. Read more about the advantages of using Sea Foam in your Bad Boy mower here.

Solution: When you have old fuel in your mower, drain the fuel tank using a fuel siphon. Add fresh fuel that includes a fuel additive to stabilize and clean your fuel system like.

Bad Boy Gas Cap or Rollover Vents Won’t Vent

Your Bad Boy mower is designed to vent and allow air into the fuel tank. When the vent becomes clogged, the fuel tank acts like a vacuum not allowing fuel to flow from the fuel tank. Your mower won’t start when it can’t get fuel.

The vent on your Bad Boy mower may be located in the fuel cap or you may have a rollover vent attached to your fuel tank. Identify if your vent is clogged by loosening the cap and starting your mower.

If your mower starts and runs fine, reinstall the fuel cap. Continue to let it run for a while to see if your mower dies because it is being starved of fuel. If your mower shuts off after letting it run for a while, there is a good chance your vent could be plugged.

Solution: When this happens, determine whether your tank is venting through the fuel cap or a rollover vent. Replace it with a new gas cap or rollover vent.

Bad Spark Plug or Loose Connection on Bad Boy Mower 

When you can’t get spark from your spark plug(s), your Bad Boy won’t start. A dirty or fouled spark plug can prevent your mower from starting. A plug with a burnt electrode, broke porcelain insulator, unsecured wires or an incorrect gap can also cause starting problems.

Solution: Remove your spark plug and inspect it for signs of carbon buildup or cracked porcelain insulator. Replace with a new spark plug(s). Make sure it is correctly gapped and the spark plug wires are secure.

Air Filter Plugged in a Bad Boy Lawn Mower

Grass clippings and dirt get stirred up when you operate your mower. This can plug your air filter if you don’t keep it clean. When the air filter is plugged, the engine can’t get the air it requires to run. It may overheat and shut down.

Running a dirty air filter or no filter at all is putting your Bad Boy’s engine at risk for serious damage. Always use an air filter in your mower.

Keep it in good condition by regularly checking and cleaning it throughout the mowing season. You will need to check it more frequently when mowing in dry dusty conditions.

Solution: I recommend starting out with a new air filter each season and then routinely clean it using these instructions for your filter type:

Clean a Bad Boy paper air filter:

  • Remove your filter from the air filter housing.
  • Wipe out any dirt remaining in the housing with a dry clean rag. Don’t allow dirt to fall into the air intake.
  • Tap your air filter against a solid surface. Knock as much dirt out of the filter as you can get loose. Don’t use compressed air to clean your filter as this will damage a filter.
  • Check for light shining through the paper filter element by holding it up to a light source.
  • If you can see light through the paper, reuse the air filter. If you can’t, replace the filter with a new one.
  • Install your air filter in the housing and reattach the air filter housing cover.

Clean a Bad Boy foam air filter:

  • Remove your filter from the air filter housing.
  • Wipe out any dirt remaining in the housing with a dry clean rag. Don’t allow dirt to fall into the air intake.
  • Inspect your filter to see if it can be reused. If you find any dark spots, rips or the filter is dry and brittle, you must replace it with a new filter. If your filter is in good condition, proceed with cleaning it.
  • Wash your foam filter with a water and a mild dish soap to remove the dirt. Rinse the filter until the water runs clear and all the soap is removed.
  • Squeeze the filter to remove the excess water and lay flat to dry. Leaving out in the sun to dry will help speed up the drying process.
  • Once the filter is dry, coat with a foam filter oil. You want it fully coated in oil, but don’t allow it to be dripping of oil.

Plugged Fuel Filter in Bad Boy Mower

It is good practice to replace your fuel filter once a year when performing your annual routine mower maintenance.

A fuel filter strains the fuel to prevent dirt and other contaminants from entering the fuel system and your engine. When dirt builds and plugs your filter, it restricts fuel flow causing starting problems.

Solution: A clogged fuel filter must be replaced with a new one. When installing a new filter, make sure the arrow on the side of the filter is pointed in the direction of the fuel flow.

Blockage in Your Bad Boy Fuel Line  

Bad or old fuel can cause clogging and damage throughout your fuel system. This includes the fuel lines as well.

You are not able to visibly see a clog in your fuel lines so you’ll have to check your hose by starting and stopping fuel flow using the fuel shut-off valve located under your fuel tank or pinch pliers to crimp your fuel line.

With your fuel flow stopped, remove one end of the fuel hose and place it into a container. Start your fuel flow and check to fuel coming out of the hose you placed in the container. Make sure the container is placed lower than the fuel tank. Fuel cannot flow uphill.

Solution: Once you find a clogged line, you need to try to remove the blockage. Do this by removing the line from your Bad Boy. Spray carburetor cleaner into the line to help loosen the blockage.

Then use compressed air to blow air into the line to remove out the blockage. Repeat this process until the clog is removed.

If you are unable to dislodge the clog, you will need to replace your fuel line. You can purchase mower fuel line at your local hardware store or online. I do recommend replacing your fuel lines, even if you don’t find a clog in them, if the fuel lines are dry and beginning to crack.

Bad Boy Fuel Pump is Bad

A fuel pump can fail over time. Old gas sitting in your fuel pump can degrade it causing it to fail. The fuel pump will no longer be able to build pressure and push fuel to the carburetor causing your Bad Boy to die.

Check for leaks on your fuel pump. If you don’t find a leak, you will need to perform a couple of tests to make sure your fuel pump is operating properly. To do this, first verify you are getting fuel to the pump by using your fuel shut off valve or pinch pliers to crimp the fuel line to stop fuel flow.

If you are unable to physically view damage or leaking, you will need to test your pump to check if it is still operating properly. Start by verifying you have flow to the fuel pump by using the shut-off valve or clamps to start and stop fuel flow.

You may have already checked this when you checked for blockages in the fuel line. If not, refer to the section “Clogged Fuel Lines” for instructions.

Once you have verified you are getting flow to the pump, check to make sure fuel is being pumped out of the pump. Do this by disconnecting the fuel hose from the carburetor and placing it in a container. Start your mower and watch the hose for a constant or pulsating fuel flow.

Solution: Replace your Bad Boy fuel pump if you are not receiving a constant or pulsating flow out of the pump.

Clogged & Dirty Carburetor on Your Bad Boy

It is common for a carburetor in your Bad Boy to become dirty and clogged from running old fuel. The function of your carburetor is to regulate the mixture of gas and air required to create a combustion in the engine’s cylinder.

When your carburetor is gummed up, your engine won’t get the right fuel and air mixture it needs to start. A dirty carburetor will need to be cleaned and any failed components must be replaced.

Solution: If you are a little mechanical you should be able to handle disassembling the small parts in your carburetor to clean your Bad Boy’s carburetor.

If you are unsure about cleaning your own carburetor, you can have your local small engine mechanic clean your carburetor or you can replace it with a new carburetor.

Clean the carburetor by taking it apart and using carb cleaner to clean the carburetor including the float bowl and needle. You can find steps for cleaning your carburetor here. If your carburetor is too dirty to clean adequately, you should replace it.

Faulty Bad Boy Mower Battery, Loose Cables or Corroded Terminals

Your Bad Boy will not start with a bad battery that won’t charge or fails to hold a charge. Loose cables or corroded terminals can also contribute to staring problems. Confirm your battery terminals are not corroded and are attached securely to the battery.

Solution: Clean corroded terminals in a baking soda solution containing 2 cups of water and 3 rounded tablespoons of baking soda. Use a wire brush to scrub the terminals clean.

Test your battery with a multimeter. You will want a reading at about 12.7 volts. Place on a charger to charge your battery if your reading is less than this.

Read more about the steps and items needed to charge your battery here. If your Bad Boy battery does not hold a charge, you will need to replace it with a new battery. 

Faulty Bad Boy Safety Switch  

Your Bad Boy lawn mower uses several safety switches designed to keep the operator safe. The manufacturer installs safety switches to prevent your mower from starting without your parking brake engaged.

It also has a safety switch that disengages your mower deck and shuts off your mower if it no longer senses the operator is present. You may have additional safety switches on your Bad Boy. When these switches fail, your Bad Boy mower will fail to start.

Solution: Test a Bad Boy switch using a multimeter. You can temporarily bypass the safety switch to identify a bad switch, but only do this for troubleshooting purposes.

Never operate a mower without the safety switch. Never run a mower when a safety switch is bypassed. A safety switch can save you from serious injury and you never know when you’re going to need it.

Faulty Bad Boy Ignition Switch or Ignition Coil 

You insert the key into your ignition switch and turn it only to find your Bad Boy doesn’t start or even turn over. The ignition switch or ignition coil could be the problem.

Solution: You can use a multimeter to test the ignition switch. Replace the switch if bad. After you have check your spark plug is working, check the continuity of your ignition coil using a multimeter. Replace the ignition coil if you find a break in the continuity.  

Faulty Charging System on Your Bad Boy Mower

A charging system that is no longer able to keep your Bad Boy mower running can cause it to die while you are mowing. It can cause your battery to be drained preventing it from starting the next time you go to use your mower.

A bad stator or alternator can also be the problem. I show steps on how to test your charging system here using an ohm meter.  

Solution: Have your local Bad Boy dealership or lawn mower small engine repair shop check your charging system to isolate the problem. If you don’t have experience with charging systems, you will most likely just be replacing electrical items until you find one that works.

This can get very expensive because most parts stores won’t let you return electrical parts if you find a part your purchased doesn’t resolve your starting problem.

Incorrect Bad Boy Operating Procedure  

Bad Boy implements safety precautions with their lawn mowers that require certain steps to be followed when starting and operating the lawn mower.

Solution: Refer to your Bad Boy operating manual to ensure you are operating your lawn mower correctly, so you don’t set off the safety features that shut off your lawn mower.