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Common Bad Boy Lawn Mower Problems & Solutions

As much as you don’t want to have failures develop in your Bad boy lawn mower, it’s bound to happen. Any mechanical item will wear down down and fail over time. You can prevent and prolong many of these problems by regularly servicing your mower.

I put together a list of the most common problems you will see as a Bad Boy lawn mower owner. This is a handy guide to keep on hand to refer to next time you encounter an issue.

The most common Bad Boy lawn mower problems are:

  • Bad Boy doesn’t start
  • Bad Boy dies while mowing
  • Bad Boy is smoking
  • Bad Boy has a weak hydrostatic transmission
  • Bad Boy won’t drive straight or steer correctly
  • Bad Boy won’t move
  • Bad Boy is shaking or vibrating
  • Bad Boy is cutting uneven
  • Bad Boy is leaking gas
Bad Boy Lawn Mower Problems and Solutions

Common Bad Boy Lawn Mower Problems & Solutions

Bad Boy Lawn Mower Won’t Start

A Bad Boy lawn mower, like all fuel-powered mowers, requires air, fuel and spark to start and run. When it lacks any of these items, your mower will fail to start.

This could be a result of old fuel, clogged fuel components, dirty carburetor, plugged air filter or bad spark plug. Your mower may also fail to start if you have electrical problems including a bad switch, ignition coil or bad battery.

Detailed information can be found at:
Your Bad Boy Lawn Mower Won’t Start: Solved!

CauseReason for ProblemSolution
No gas in the fuel tankFuel tank is emptyFill with fresh fuel
Bad or old fuelFuel breaks down overtime making your fuel less efficient and prone to clogging the fuel systemDrain the fuel tank and fill with fresh fuel. Use a fuel additive like Sea Foam to stabilize the fuel and assist with cleaning the fuel system. Use the right fuel.
Faulty or clogged fuel capThe vent in the cap can get clogged causing your tank to form a vacuum restricting fuel flowTry to clean the cap and remove the clogged vent. Replace the cap if needed.
Bad spark plugExcessively dirty or broken spark plug; bad connection; not gapped correctlyReplace with a new spark plug, secure connections and ensure it is gapped to manufacturer specifications
Plugged air filterDirt and grass can plug the air filter preventing air flowRemove the filter and clean it. Replace the filter if it is in bad condition.
Plugged fuel filterA dirty fuel filter will restrict fuel flowReplace the fuel filter
Bad fuel pumpA failed or leaking fuel pump will no longer create pressure needed to pump fuelReplace the fuel pump
Blocked fuel linesBad fuel deposits and dirt can build up and clog the fuel lines preventing the engine from getting the required fuelUse a carb cleaner and compressed air to clear the clog out of the fuel line. Replace line if necessary.
Dirty carburetorThe carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flowClean the components making up the carburetor. Replace if needed.
Bad battery or loose & dirty terminalsA dead battery, loose cables or corroded terminals can cause starting problemsCharge your battery and replace if it won’t hold a charge. Make sure your cables are tight and clean the corrosion from terminals.
Bad safety switchSafety switches is a safety measure that exist to prevent your mower from starting in certain situations. When a switch fails, your mower may not start.Test and replace faulty safety switch
Bad ignition switch or coilYour mower will not start when either the ignition switch or coil is badTest and replace a bad switch
Broken recoilA pull start mower may have a damaged or broke recoil preventing the recoil to initiate starting your engineCheck recoil to see if it can be restrung or broke parts, like the pulley, can be replaced. Replace the recoil assembly if needed.
Bad charging systemA charging system that can’t keep your mower charged and is constantly draining the battery must be repaired to prevent starting problems.Take your lawn mower to your local Bad Boy dealer for assistance identifying which part of the charging system has failed.
Reasons Your Bad Boy Mower Won’t Start

Bad Boy Lawn Mower Loses Power and Dies

A Bad Boy mower can lose power and shut off when the mower has a fuel or air restriction from running bad fuel that clogs fuel components or from using a plugged air filter.

Your mower may also shut down when it overheats. Overheating can be caused by a lack of air to the engine, a plugged engine cooling fan or an insufficient engine oil level.

Not only is it important to check for items that can restrict air, fuel or cause your mower to overheat, you need to look at your battery, charging system, spark plug and engine coil as well. These items can be the culprit of your mower’s running problem.

Detailed information can be found at:
Your Bad Boy Mower Starts Then Dies

CauseReason for ProblemSolution
Bad fuelFuel breaks down overtime making your fuel less efficient and prone to clogging the fuel system and engine damageDrain the fuel tank and fill with fresh fuel. Use a fuel additive like Sea Foam to stabilize the fuel and assist with cleaning the fuel system
Plugged air filterDirt and grass can plug the air filter preventing air flowRemove the filter and clean it. Replace the filter if it is in bad condition.
Dirty or broken cooling finsCooling fins get packed with dirt, oil and grass not allowing air to effectively cool the engine blockReplace broken fins and clean the cooling fins.
Clogged fuel lines or filterBad fuel deposits and dirt can build up and clog the fuel lines preventing the engine from getting the required fuelUse a carb cleaner and compressed air to clear the clog out of the fuel line. Replace a plugged fuel filter.
Dirty carburetorThe carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flowClean all components making up the carburetor. Replace if needed.
Too Much Engine OilToo much engine oil increases pressure in the crankcase causing it to overheat and dieCorrect your engine oil level by removing a little oil
Bad Spark PlugDirty or damaged spark plug causes plug to foul out and cause intermittent running problems.Clean or replace spark plugs if needed. Ensure spark plug wires are securely attached and the plug is gapped correctly.
Faulty Ignition CoilA windings on the coil can separate and short out on a bad ignition coilCheck for a break in the continuity using an ohm meter and replace is found bad
Choke is in the Wrong PositionA choke is used for cold starts. The choke can cause your engine to shut off when it continues to restrict airflow after the engine warms.Make sure the choke is in the correct position
Battery is Not ChargingA battery that doesn’t hold a charge or a bad charging system that can’t keep the battery charged will cause your Bad Boy to die after running.Test your battery and charging system. Replace any electrical components found to be bad. Read more about testing your battery and charging system here.
Bad Gas Cap or Rollover VentsA Bad Boy mower will vent the tank to allow air to pass through. When the vents get plugged, the fuel tank will cause fuel restrictions.Replace a fuel cap or rollover vents when they become clogged and no longer vents
Clogged Mower DeckClogged mower deck causes a strain on the engine causing it to work hard and possibly shut downPeriodically scrape your mower deck to keep it clean
Reasons Why Your Bad Boy Mower Dies While Mowing

Bad Boy Lawn Mower is Smoking

Smoking can be alarming. It may be the result of water in the fuel system or oil burning off a hot component. An engine oil leak or spill can cause a smoke when the oil burns off of a hot component like the engine or muffler.

A smoking Bad Boy mower may be the result of a plugged air filter, insufficient engine oil level, engine gasket leak, valve train problem or piston ring problem.

Detailed information can be found at:
Why Your Bad Boy Lawn Mower is Smoking
– Article Coming Soon

CauseReason for ProblemSolution
Plugged air filterDirt and grass can plug the air filter preventing air flowRemove the filter and clean it. Replace the filter if it is in bad condition.
Too much oil in the crankcaseExcessive oil can cause pressure to build in the engine allowing oil to get into the cylinder through the valve trainDrain a little engine oil until it is at the manufacturers recommended oil level.
Engine oil level is too lowLack of oil can increase friction in your engine causing extreme heat.Bring to a small engine repair shop to inspect engine damage. You can try adding oil, but it is often too late to have this fix your engine problem.
Internal problems including the piston ring, valve train or engine gasketInternal engine problems can have a detrimental effect on your mower if they are not caught soon enough and fixed.Bring your Bad Boy mower to your local small engine repair shop for troubleshooting
Reasons Why Your Bad Boy Mower is Smoking

Bad Boy Lawn Mower Has a Weak Hydrostatic Transmission 

A hydrostatic transmission on a Bad Boy lawn mower can feel weak from the use of a bad hydraulic belt or pulley. Old hydraulic oil or not having enough oil in the hydraulic tank can also result in a weak transmission.

Note: Some transmissions are non-serviceable. This means you are unable to change the hydraulic oil because the system is sealed.

Bring your mower to your local lawn mower repair shop or Bad Boy dealership when you have problems with a non-serviceable hydraulic system.

CauseReason for ProblemSolution
Bad drive beltA bad drive belt can cause your pump not to work efficientlyReplace a frayed, cracked or worn belt
Bad tensioner pulleyWhen a tensioner pulley fails, it fails to keep tension on the drive beltReplace the pulley and grease the tensioner arm
Low or old hydraulic oilLow or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weakChange your hydraulic oil at regularly intervals as recommended by Bad Boy.
Check your hydraulic oil periodically to ensure your hydraulic fluid is full.
Reasons Why Your Bad Boy Mower’s Hydrostatic Transmission Seems Weak

Bad Boy Lawn Mower Won’t Drive Straight or Steer Correctly

Several items can affect your Bad Boy mower’s steering including incorrect tire pressures and worn steering dampers. It is good to check the tracking on your mower.

When the unit is not tracked correctly, your mower can veer off to one side and not drive straight.

CauseReason for ProblemSolution
Incorrect tire pressureUnequal tire pressure can cause your mower to pull to one side.Check tire pressures and keep them filled to the manufacturers spec. Tires on each side of your mower requires equal pressures.
Bad dampers on zero turnBad dampers will cause your mower to jerk to one side when moving forwardReplace with a new damper
Tracking adjustment needed on zero turnWhen one tire is moving faster than the other, your mower can pull to one sideAdjust speed adjustment bolt to change the rotation speed of the tire. Refer to your owner’s manual.
Reasons Why Your Bad Boy Mower Won’t Drive Straight or Steer Correctly

Bad Boy Lawn Mower Won’t Move

Before you check anything on your Bad Boy mower, first check to drive release arms are not the cause of your moving problem. These arms are located at the rear of your mower on the right and left hand.

The arms will be pulled out to place your mower in the neutral position to disengage the hydros so you can manually roll the mower. Make sure these arms are in the operating position.

Note: Some Bad Boy mowers use a bypass actuator screw on each transaxle housing to disengage the hydrostatic transmission. Refer to your owner’s manual to determine which type of valve you own.

A bad drive belt, broken tensioner spring or a worn tensioner pulley can all cause your Bad Boy mower not to move. A problem in your hydraulic system where the fluid is hot, at a low level or air is caught in the system can cause your mower to move slowly or not move at all.

Again, some hydraulic systems are sealed so you won’t be able to work on it. Take your mower in for repair to your local Bad Boy mower dealership.

You may also want to check your drive release levers. If they are not in the operating position, your mower will not move.

Detailed information can be found at:
9 Reasons Your Mower Won’t Move or Go Forward

CauseReason for ProblemSolution
Drive release lever in the wrong positionThe drive release arms allows hydrostatic mowers to roll freelyThe drive release arms must be in the operating position.
Drive pump belt is wornThe mower won’t move if your drive belt has fallen off. It could also not move if the belt is worn.Replace a worn or cracked belt. Make sure the belt is securely around the pulleys.
Bad tensioner pulleyThe bearing in the tensioner pulley can failReplace the tensioner pulley
Missing idler arm springIf the idler arm spring breaks or goes missing, it can no longer place tension on the drive beltReplace the broken or missing spring
Low or old hydraulic oilLow or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weakChange your hydraulic oil at regularly intervals as recommended by Bad Boy.
Check your hydraulic oil periodically to ensure your hydraulic fluid is full.
Hot hydraulic fluidHot hydraulic fluid can be a sign of damage to your hydrostatic transmission systemLet your hydraulic oil cool. If you find your mower runs fine when it is cold, but does becomes weak when the hydraulic system gets hot, have your mower checked at your local Bad Boy dealership.
Air in the hydraulic systemAir must be bled from the hydraulic system after changing your hydraulic fluid or the mower will not be able to move at normal speedsFollow Bad Boy’s procedures for changing hydraulic fluid and bleeding air from the system as outlined in your owner’s manual.
Reasons Why Your Bad Boy Will Not Move or Go Forward

Bad Boy Lawn Mower is Vibrating

Your Bad Boy mower naturally vibrates when operating normally. This vibration can intensify when there are loose or broken parts on your mower or your mower has worn linkages, a bad clutch, or debris stuck in your mower. Even the smallest little item can cause a significant vibration so inspect your mower closely.

Bad deck components can also cause your Bad Boy mower to shake. This can from unbalanced mower blades; worn bearings in the spindle housings and pulleys; a worn belt; or bent brackets.

Detailed information can be found at:
Your Bad Boy Lawn Mower is Vibrating

CauseReason for ProblemSolution
Loose or missing engine mounting boltsEngine bolts are used to reduce vibration of the mower when the engine is runningSecure engine bolts and replace any missing bolts
Clutch is badWhen there is bearing failure and it falls out of the clutch it can cause vibration. A manual engagement clutch can have a bushing and linkages that can fail.Replace the clutch
Unbalanced or damaged mower bladesDamaged and unbalanced blades can send a vibration through your mower. Blades must be balanced before installingReplace any damaged blades and make sure they are balanced.
Material wrapped around the blade spindleForeign materials like string or long weeds can get wrapped around your blade shaft causing vibrationRemove all debris and items wrapped around the blade shaft. Check for spindle damage.
Bad spindle housing bearingsVibration can be caused by a bad bearing in the spindle housing.Replace bearing in the spindle housing or replace the whole spindle housing assembly
Worn pulleys or deck beltCheck deck belt and pulleys for wearing of the belt and bearing failure in the pulleysReplace any damaged or worn belts and pulleys
Debris lodged in mowerThe smallest little things can cause your Bad Boy to excessively vibrate. Check over your mower for debris stuck in the deck or mower. Don’t overlook the small stuff.Check over your mower deck and mower for any place small items can be stuck in your mower. Remove these foreign materials.
Reasons Your Bad Boy Mower is Vibrating

Bad Boy Lawn Mower Has a Bad or Uneven Cut

An uneven cut with your Bad Boy mower isn’t always a problem in the mower deck. It can be something as simple as a low tire that can make you’re your mower not sit level.

Always check the tire pressure first and then move on to looking at your mower deck.

Detailed information can be found at:
Reasons Your Bad Boy Lawn Mower Cuts Uneven

Worn mower bladeUneven tire pressuresEngine speed is too low
Bent mower bladeUnleveled mower deckGround speed is too fast
Blade installed wrongBent blade spindle or spindle bearingDamaged deck shell
Clogged Mower DeckWorn deck pulleys or beltOperator error
Reasons Your Bad Boy Mower is Cutting Uneven

Bad Boy Lawn Mower is Leaking Gas

Locating the actual spot your Bad Boy lawn mower is leaking can be more challenging that you might think. You may not notice you have a gas leak until you see a trail of burnt grass or smell a strong odor in your storage shed.

By the time you get to looking at your mower, the leaked fuel may have already evaporated into the air leaving no clues.

Your mower can develop leaks in the fuel system because old grass degrades your components over time. It can make mechanical parts fail or cause plastic housings to become weak and leak.

Detailed information can be found at:
Your Bad Boy Mower is Leaking Gas

CauseReason for ProblemSolution
Dirty of Failed CarburetorThe carburetor can collect a buildup of substances remaining from old gas that can cause blockages or parts failuresClean the carburetor and replace any damaged parts
Old Fuel FilterFilter can become pluggedReplace fuel filter
Bad Fuel PumpPump can wear and deteriorate over time and may begin leaking at the seamsReplace the fuel pump
Bad Fuel TankA poly tank can leak at the seams of the tank.Replace the fuel tank.
Bad Fuel Shut-Off ValveMetal and plastic shut-off valves are prone to leakingReplace the shut-off valve
Cracked Fuel LinesRubber fuel lines become dry and cracked causing gas to leakReplace the fuel lines
Bad Seal in the Gas CapThe gas cap seal can fail and no longer seal allowing gas to splash out of the fuel tank around the gas capReplace the gas cap
Places Your Bad Boy Mower May Be Leaking Gas