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9 Common Gravely Lawn Mower Problems & Solutions

Even though Gravely makes a well-built lawn mower, it will not be problem free. Like with any mechanical item you purchase, when you own it long enough, you’re bound to run into a problem. I put together this guide to help you identify causes to the problems that develop in your Gravely lawn mower.

The most common Gravely lawn mower problems are:

  • Gravely mower doesn’t start
  • Gravely mower starts then dies
  • Gravely mower is smoking
  • Gravely mower has a weak hydrostatic transmission
  • Gravely mower won’t drive straight or steer correctly
  • Gravely mower won’t move
  • Gravely mower is shaking or vibrating
  • Gravely mower is cutting uneven
  • Gravely mower is leaking gas

To keep your mower running at it’s best, regularly clean your mower, check the engine oil and hydraulic oil, clean the air filter, sharpen the blades and scrape the deck. Perform routine oil changes as required for your Gravely mower. Check out this guide on servicing your Gravely zero turn.

Common Gravely lawn mower problems

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Follow all safety instructions provided in your equipment operators 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.

Common Gravely Lawn Mower Problems & Solutions

Gravely Lawn Mower Won’t Start

A Gravely lawn mower requires air, fuel and spark to start and run. When it lacks any of these three items, it will fail to start. The items that can keep your mower from starting are old fuel; plugged air filter; clogged fuel lines; plugged fuel pump; dirty carburetor; dirty spark plug; bad ignition switch; bad battery; and faulty charging system.

Detailed information can be found at:
Your Gravely 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
Reasons Your Gravely Mower Won’t Start

Gravely Lawn Mower Starts Then Dies

Many of the items that can prevent your Gravely lawn mower from starting will also cause it to shut down after running. In addition to these items, the mower can overheat and shut down. This can be the result of a plugged air filter; plugged or broken cooling fan; or an insufficient oil level.

Check for a bad ignition coil, plugged mower deck, bad gas cap or incorrect choke setting as well. These items can cause the mower to die after it starts.

Detailed information can be found at:
Your Gravely 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 Gravely mower 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 CapGas caps have vents for air to pass through. When the vents get plugged, the fuel tank will cause fuel restrictions.Replace a fuel cap that 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 Gravely Mower Dies While Mowing

Gravely Lawn Mower is Smoking

Smoke coming from a Gravely lawn mower can be caused by something as simple as a spilled oil when completing an oil change. Oil burning off a hot engine or muffler can cause the mower to smoke. Smoke can also indicate you have a more serious problem developing in the mower. This could be a valve or piston ring problem.

Detailed information can be found at:
Your Gravely Mower is Blowing Blue, Black or White Smoke: Find Out Why!

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 Gravely mower to your local small engine repair shop for troubleshooting
Reasons Why Your Gravely Mower is Smoking

Gravely Lawn Mower Has a Weak Hydrostatic Transmission 

A hydrostatic transmission on a Gravely 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.

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 Gravely.
Check your hydraulic oil periodically to ensure your hydraulic fluid is full.
Reasons Why Your Gravely Mower’s Hydrostatic Transmission Seems Weak

Gravely Lawn Mower Won’t Drive Straight or Steer Correctly

Several items can affect your Gravely 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 Gravely Mower Won’t Drive Straight or Steer Correctly

Gravely Lawn Mower Won’t Move

Before you check anything on your Gravely mower, first check to drive bypass valves are not the cause of your moving problem. These are valves located at the rear of your mower that disengages the hydros so you can manually push the mower. When these valves are bypassed, the mower will free roll, but will not drive. Make sure the bypass valves are in the operating position.

Once you confirm the bypass valves are not the problem, check for a bad drive belt, broke tensioner spring or worn tensioner pulley. 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.

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 Gravely.
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 Gravely 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 Gravely’s procedures for changing hydraulic fluid and bleeding air from the system as outlined in your owner’s manual.
Reasons Why Your Gravely Will Not Move or Go Forward

Gravely Lawn Mower is Vibrating

Mowing with your Gravely mower isn’t always the most comfortable task even if you have a nice suspension seat installed. Running your mower over uneven ground can have you bouncing around on your mower. Add a severe vibration in your mower, you may feel like you’re going to shake right out of your seat.

Small debris lodged in your Gravely mower, worn engine mounting bolts or bad mower deck components can cause a vibration.

Detailed information can be found at:
Your Gravely Lawn Mower Vibration

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 Gravely 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 Gravely Lawn Mower is Vibrating

Gravely Lawn Mower Has a Bad or Uneven Cut

An uneven cut with your Gravely mower isn’t always a problem in the mower deck. It can be something as simple as a low tire that can cause 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 Gravely 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 Gravely Lawn Mower is Cutting Uneven

Gravely Lawn Mower is Leaking Gas

Locating the actual spot your Gravely 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 Gravely 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 Gravely Mower May Be Leaking Gas