While performing regular maintenance on your mower can minimize the problems that develop, you can’t avoid them all.
At some time, something is bound to wear, break or seize that can cause the mower to not start, begin smoking, fail to move, leak fuel, or just give you a bad cut. I provide tables with causes and solutions to your Ferris zero-turn issues.
To minimize common problems on your lawn mower, perform routine maintenance. This includes checking the air filter and engine oil level and looking for fuel & oil leaks before each use.
Then clean the mower after each use to keep debris off the mower.
Several times a season, you should scrape the deck and lubricate the required components like the spindles and castor wheels. Don’t skip the annual full maintenance on your mower.
You’ll need to do these things more often if you use the mower for commercial purposes.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
Table of Contents hide
1. Starting Problem
2. Starts Then Dies Problem
3. Smoking Problems
4. Hydrostatic Transmission Problems
5. Won’t Drive Straight or Steer Correctly Problem
6. Won’t Move
7. Vibrating and Shaking
8. Cuts Bad or Uneven Cut Problem
9. Leaking Gas
11. Blades Won’t Engage or Turn On Problems
12. Running Rough and Sputters Problems
13. Engine Overheats
Common Ferris Zero Turn Mower Problems & Solutions
I have put together some quick reference guides for identifying the cause and solutions for many issues that may develop in your mower.
You will also find links to more detailed articles about common zero turn mower problems and how to repair them.
1. Starting Problem
A zero-turn or walk-behind mower can have trouble starting when it isn’t getting the spark, fuel, and air required to form combustion in the cylinder.
To solve this common problem, you’ll need to look for items that can cause an air restriction like a stuck choke or plugged air filter. You’ll also need to check for a fuel restriction due to a fuel component failure or a clogged fuel line or fuel filter.
Other issues that may affect your starting problem are a bad spark plug, bad wiring, bad battery, and loose cables.
Detailed information can be found at:
14 Reasons Your Ferris Lawn Mower Won’t Start
| Cause | Reason for Problem | Solution |
| No gas in the fuel tank | Fuel tank is empty | Fill with fresh fuel |
| Bad or old fuel | Fuel breaks down overtime making your fuel less efficient and prone to clogging the fuel system | Drain the fuel tank and fill it 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 cap | The vent in the cap can get clogged causing the fuel tank to form a vacuum restricting fuel flow | Replace a clogged fuel tank cap. |
| Bad spark plug | Excessively dirty or broken spark plug; bad connection; not gapped correctly | Replace with a new spark plug, secure connections, and ensure it is gapped to manufacturer specifications |
| Plugged air filter | Dirt and grass can plug the air filter preventing airflow | Remove the filter and clean it. Replace the filter if it is in bad condition. |
| Plugged fuel filter | A dirty fuel filter will restrict fuel flow | Replace the fuel filter |
| Bad fuel pump | A failed or leaking fuel pump will no longer create the pressure needed to pump fuel | Replace the fuel pump |
| Blocked fuel lines | Bad fuel deposits and dirt can build up and clog the fuel lines preventing the engine from getting the required fuel | Use a carb cleaner and compressed air to clear the clog out of the fuel line. Replace the line if necessary. |
| Dirty carburetor | The carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flow | Clean the components making up the carburetor. Replace if needed. |
| Bad battery or loose & dirty terminals | A dead battery, loose cables, or corroded terminals can cause starting problems | Charge your battery and replace it if it won’t hold a charge. Make sure your cables are tight and clean the corrosion from terminals. |
| Bad safety switch | Safety switches are a safety measure that exists 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 coil | Your mower will not start when either the ignition switch or coil is bad | Test and replace a bad switch |
2. Starts Then Dies Problem
Another frustrating common problem owners may deal with is a mower that keeps dying after it’s been running. Most of the issues that will prevent a lawn mower from starting can also be the reasons a mower may quit running.
In addition to checking the fuel, air, and spark problems addressed earlier, look for a faulty ignition coil; an incorrect engine oil level; dirty or broke cooling fins; or a clogged mower deck.
Detailed information can be found at:
13 Reasons a Ferris Lawn Mower Starts Then Dies: SOLVED!
| Cause | Reason for Problem | Solution |
| Bad fuel | Fuel breaks down overtime making your fuel less efficient and prone to clogging the fuel system and engine damage | Drain the fuel tank and fill it with fresh fuel. Use a fuel additive like Sea Foam to stabilize the fuel and assist with cleaning the fuel system |
| Plugged air filter | Dirt and grass can plug the air filter preventing airflow | Remove the filter and clean it. Replace the filter if it is in bad condition. |
| Dirty or broken cooling fins | Cooling fins get packed with dirt, oil, and grass not allowing air to effectively cool the engine block | Replace broken fins and clean the cooling fins. |
| Clogged fuel lines or filter | Bad fuel deposits and dirt can build up and clog the fuel lines preventing the engine from getting the required fuel | Use a carburetor cleaner and compressed air to clear the clog out of the fuel line. Replace a plugged fuel filter. |
| Dirty carburetor | The carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flow | Clean all components making up the carburetor. Replace if needed. |
| Too Much or Too Little Engine Oil | Too much engine oil increases pressure in the crankcase causing it to overheat and die. Too little oil doesn’t provide the lubrication parts needed causing it to overheat and shut down. | Correct your engine oil. Contact a small engine mechanic when this doesn’t correct your issue. You may have developed a significant engine issue. |
| Bad Spark Plug | A dirty or damaged spark plug causes the 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 Coil | Windings on the coil can separate and short out on a bad ignition coil | Check for a break in the continuity using an ohm meter and replace is found bad |
| Choke is in the Wrong Position | A 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. |
| Bad Fuel Tank Vent | Gas tanks require vents for air to pass through. When the vents get plugged, the fuel tank will cause fuel restrictions. | Replace a fuel tank vent that no longer vents. |
| Clogged Mower Deck | A clogged mower deck causes a strain on the engine causing it to work hard and possibly shut down | Periodically scrape your mower deck to keep it clean |
3. Smoking Problems
When your mower starts blowing white, black, or blue smoke you’re going to need to identify and repair the problem before it develops into a bigger one.
First off, stop running the mower. Allow the mower to cool before working on it. A few things to look for are a plugged air filter, too much oil in the crankcase, or a leaking engine gasket.
If you find one of these issues, you need to repair it. When these items are caught and repaired soon enough, you shouldn’t have significant engine problems.
Other more serious items to look for are a low engine oil level or internal engine problems. These are serious zero-turn mower problems that may require a small engine mechanic to perform tests to diagnose and perform necessary repairs accurately.
Detailed information can be found at:
| Cause | Reason for Problem | Solution |
| Plugged air filter | Dirt and grass can plug the air filter preventing airflow | Remove the filter and clean it. Replace the filter if it is in bad condition. |
| Too much oil in the crankcase | Excessive oil can cause pressure to build in the engine allowing oil to get into the cylinder through the valve train | Drain a little engine oil until it is at the manufacturer’s recommended oil level. |
| Engine oil level is too low | Lack 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 issue. |
| Internal problems including the piston ring, valve train, or engine gasket | Internal engine problems can have a detrimental effect on your mower if they are not caught soon enough and fixed. | Bring your mower to your local small engine repair shop or Ferris dealer for troubleshooting |
4. Hydrostatic TransmissionProblems
A hydrostatic transmission on a 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 lack of power from the transmission.
| Cause | Reason for Problem | Solution |
| Bad drive belt | A bad drive belt can cause your pump not to work efficiently | Replace a frayed, cracked, or worn belt |
| Bad tensioner pulley | When a tensioner pulley fails, it fails to keep tension on the drive belt | Replace the pulley and grease the tensioner arm |
| Low or old hydraulic oil | Low or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weak | Change your hydraulic oil at regular intervals as recommended by Ferris. Check your hydraulic oil periodically to ensure your hydraulic fluid is full. |
5. Won’t Drive Straightor Steer Correctly Problem
Several items can affect your 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.
| Cause | Reason for Problem | Solution |
| Incorrect tire pressure | Unequal tire pressure can cause your mower to pull to one side. | Check tire pressures and keep them filled to the manufacturer’s spec. Tires on each side of your mower require equal pressure. |
| Bad dampers on zero turn | Bad dampers will cause your mower to jerk to one side when moving forward | Replace with a new damper |
| Tracking adjustment needed on zero turn | When one tire is moving faster than the other, your mower can pull to one side | Adjust the speed adjustment bolt to change the rotation speed of the tire. Refer to your owner’s manual. |
6. Won’t Move
Before you check anything on your mower, first check the 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 issue, check for a bad drive belt, broken tensioner spring, or worn tensioner pulley.
Ferris mower problems 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:
Reasons Your Ferris Zero Turn Mower Won’t Move or Go Forward
| Cause | Reason for Problem | Solution |
| Drive release lever in the wrong position | The drive-release arms allow hydrostatic mowers to roll freely | The drive-release arms must be in the operating position. |
| Drive pump belt is worn | The 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 pulley | The bearing in the tensioner pulley can fail | Replace the tensioner pulley |
| Missing idler arm spring | If the idler arm spring breaks or goes missing, it can no longer place tension on the drive belt | Replace the broken or missing spring |
| Low or old hydraulic oil | Low or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weak | Change your hydraulic oil at regular intervals as recommended by Ferris. Check your hydraulic oil periodically to ensure your hydraulic fluid is full. |
| Hot hydraulic fluid | Hot hydraulic fluid can be a sign of damage to your hydrostatic transmission system | Let your hydraulic oil cool. If you find your mower runs fine when it is cold, but becomes weak when the hydraulic system gets hot, have your mower checked at your local Ferris dealership. |
| Air in the hydraulic system | Air must be bled from the hydraulic system after changing your hydraulic fluid or the mower will not be able to move at normal speeds | Follow the procedures for changing the hydraulic fluid and bleeding air from the system as outlined in your operator’s manual. |
7. Vibrating and Shaking
A mower may begin vibrating when hardware has become loose, debris has lodged itself in the mower, the ball bearing in the clutch has failed, or bearings in the pulleys have worn.
Check the mower over carefully to make sure all parts are in good condition and properly installed. Remove any foreign material and keep the mower deck clean and free of debris.
Detailed information can be found at:
| Cause | Reason for Problem | Solution |
| Loose or missing engine mounting bolts | Engine bolts are used to reduce the vibration of the mower when the engine is running | Secure engine bolts and replace any missing bolts |
| Clutch is bad | When there is bearing failure and it falls out of the clutch it can cause vibration. | Replace the clutch |
| Unbalanced or damaged mower blades | Damaged and unbalanced blades can send a vibration through your mower. Blades must be balanced before installing | Replace any damaged blades and make sure they are balanced. |
| Material wrapped around the blade spindle | Foreign materials like string or long weeds can get wrapped around your blade shaft causing vibration | Remove all debris and items wrapped around the blade shaft. Check for spindle damage. |
| Bad spindle housing bearings | Vibration can be caused by a bad bearing in the spindle housing. | Replace the bearing in the spindle housing or replace the whole spindle housing assembly |
| Worn pulleys or deck belt | Check deck belt and pulleys for wearing of the belt and bearing failure in the pulleys | Replace any damaged or worn belts and pulleys |
| Debris lodged in mower | The smallest little things can cause your Ferris to vibrate excessively. 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. |
8. Cuts Bad or Uneven Cut Problem
One of the main reasons you invested in your mower is because it cuts well. It’s disappointing when the mower begins to fail to give you the cut you expect.
To narrow down the cause of your bad or uneven cut, first, start by checking the tire pressures. Something as simple as a low tire will give you a bad cut because the deck will no longer sit level.
Once you have ruled out the tire pressures being wrong, you’ll need to look at your deck. The mower blades; deck belt; spindle; spindle or pulley bearings; or deck shell all affect how your zero-turn cuts.
Detailed information can be found at:
Your Ferris Lawn Mower Give a Bad Cut: Solved!
| Worn mower blade | Uneven tire pressures | Engine speed is too low |
| Bent mower blade | Unleveled mower deck | Ground speed is too fast |
| Blade installed wrong | Bent blade spindle or spindle bearing | Damaged deck shell |
| Clogged Mower Deck | Worn deck pulleys or belt | Operator error |
9. Leaking Gas
Oftentimes, you notice you have a fuel leak when you see a small puddle on the ground. Other times you will only smell a strong gas odor in the air because the leaked gas has evaporated leaving no other signs behind.
A fuel leak from your mower may come from the carburetor due to a failed gasket or stuck float. It can also leak from a fuel filter, fuel shut-off valve, gas cap, fuel lines, or fuel pump.
Detailed information can be found at:
7 Places Your Ferris Lawn Mower May Be Leaking Gas
| Cause | Reason for Problem | Solution |
| Dirty of Failed Carburetor | The carburetor can collect a buildup of substances remaining from old gas that can cause blockages or parts failures resulting in a leak | Clean the carburetor and replace any damaged parts |
| Old Fuel Filter | The filter can become soft and degrade from old fuel | Replace fuel filter |
| Bad Fuel Pump | The pump can wear and deteriorate over time and may begin leaking at the seams | Replace the fuel pump |
| Bad Fuel Tank Seams | A poly tank can leak at the seams of the tank | Replace the fuel tank. |
| Bad Fuel Shut-Off Valve | Shut-off valves are prone to leaking with time | Replace the shut-off valve |
| Cracked or Punctures Fuel Lines | Rubber fuel lines become dry and cracked causing gas to leak. They can also be punctured by a foreign object or the clamps used on the lines. | Replace the fuel lines |
| Bad Seal in the Gas Cap | The gas cap seal can fail and no longer seal allowing gas to splash out of the fuel tank around the gas cap | Replace the gas cap |
10. Clicks & Won’t Turn Over Problems
A zero-turn that just clicks or hums and won’t start may have a bad starter solenoid. In addition to checking the solenoid, look for items that can affect power getting to the solenoid.
These include the battery, cables, terminals, and ground. When the fault doesn’t lie with any of these items, check the starter motor.
For More Information Check Out:
| Cause | Reason for Problem | Solution |
|---|---|---|
| Damaged or loose battery cables & wiring | Loose wires and cables provide poor continuity. | Replace damaged cables. Remove any corrosion on the terminals or other components. Secure loose cables. |
| Weak or bad battery | Won’t provide the power needed to turn over the engine. | Test the battery and place it on a charger if the reading is less than 12.7 volts for a 12-volt battery. Replace the battery when it won’t hold a charge. |
| Bad ground | The ground wire absorbs excess power. | Remove corrosion from the ground. Make sure the ground cable from the battery and ground cable from the starter solenoid is making good contact. (A 3-post solenoid is self-grounded) |
| Faulty starter solenoid | The starter solenoid actuates the starter motor. | Test the starter solenoid and replace it if faulty. |
| Bad starter motor | The starter motor turns over the engine. | Replace a bad starter motor. |
11. Blades Won’t Engage or Turn On Problems
The mower blades won’t engage on a zero turn when the PTO switch is faulty, the battery is weak, a safety switch failed or the clutch is bad.
The blades won’t turn when the belt is worn or has fallen off the pulleys due to a stretched belt, bad pulley bearing, or worn tensioner parts.
For More Information Check Out:
Ferris Lawn Mower Blades Won’t Engage or Turn On
| Cause | Reason for Problem | Solution |
|---|---|---|
| Worn mower deck belt | The worn belt won’t grip the pulleys to turn them to rotate the blades. | Replace a belt that is worn, cracked, or has a shiny glazed appearance. |
| Belt falls off the pulleys | Without a drive belt, the pulleys can’t turn to rotate the blades. | Replace worn or damaged deck parts including a worn idler arm, worn spring or bad pulleys. Replace a stretch mower deck belt. |
| Bad PTO switch | A failed switch won’t allow voltage from the battery to engage the clutch. | Replace the PTO switch. |
| Bad clutch | The clutch transfers power from the engine to the blades by engaging the drive belt. | Replace the clutch. On a manual engagement clutch, replace a worn clutch cable, lever, springs, and linkages. |
| Weak battery | The clutch is powered by the battery. | Test the battery and place it on a charger if the reading is less than 12.7 volts for a 12-volt battery. Replace the battery when it won’t hold a charge. |
| Bad safety switch | A bad switch may not allow the operator to engage the blades when the seat switch fails to recognize the operator in the seat. | Replace the safety switch |
| Blown fuse | A fuse may have blown to protect the electrical system. | Replace the fuse with a fuse with the same amperage. If it continues to blow, have a mechanic identify the root cause of the problem. |
12. Running Rough and Sputters Problems
When you find your zero-turn is running rough and bogs down, begin troubleshooting by looking for items that can restrict fuel flow or airflow or can cause an intermittent spark.
You’ll also need to look at items that can put extra load on the engine like a fast ground speed, plugged mower deck, and dull mower blades. Not having your throttle at its fastest speed can also cause the engine to run sluggishly when the blades are engaged.
For More Information Check Out:
Ferris Zero Turn Mower is Running Rough or Sputtering
| Cause | Reason for Problem | Solution |
|---|---|---|
| Old fuel | Old fuel buildup and varnish restrict fuel flow. | Drain old fuel. Refill with a gas and fuel stabilizer mixture. |
| Clogged fuel line | Old fuel deposits can stick to the fuel line narrowing the passageway through the fuel line. | Remove a clogged fuel line and remove the clog using carburetor cleaner and compressed air. Install a new fuel line when the clog can’t be removed. |
| Plugged fuel filter | A dirty fuel filter may keep a good flow of fuel from passing through it. | Replace the fuel filter. |
| Dirty carburetor | Varnish buildup can clog passageways. | Remove the carburetor to clean it. Rebuild or replace it if needed. |
| Bad gas cap | When the fuel tank vent in the gas cap is clogged, the fuel tank may form a vacuum reducing fuel flow. | Replace a gas cap that no longer allows the fuel tank to vent. |
| Dirty spark plug | Carbon buildup on a spark plug can cause intermittent starting problems. | Clean a dirty plug using a wire brush. Install a new one if it is very dark in color, worn, or damaged. |
| Fast ground speed | Trying to cut more grass at one time than the engine can handle can cause the engine to work harder. | Slow down the ground speed to match the mowing conditions. Slow down when mowing tall, thick, or wet grass so the engine isn’t under too much load. |
| Low engine speed | Running the mower blades requires a lot of engine power. | Place the throttle lever in its highest position when engaging the mower blades. |
| Plugged mower deck | The engine may be placed underload when it needs to work harder to turn the blades through a deck packed with grass clippings and debris. | Scrape the mower deck to keep it clean. |
| Dull mower blades | Dull blades further magnify the problem of overworking the engine due to a plugged mower deck. | Sharpen the mower blades. |
13. Engine Overheats
Engine oil plays an important part in keeping the engine cool on a zero-turn mower. Use an air-cooled engine oil of the right viscosity that is high in zinc. Keep the engine oil level full.
Check for items that can block airflow around the engine including the cooling fins, engine shroud, and engine guard.
Inspect the air filter, mower deck, and mower blade condition to prevent common overheating problems.
For More Information Check Out:
Ferris Zero Turn Mower Engine Overheats (Coming Soon)
| Potential Cause | Solution | |
|---|---|---|
| Wrong engine oil | A Ferris lawn mower requires an air-cooled engine oil with a high zinc content used as a cooling agent. Use oil that works best in for running a mower in your outdoor temperature ranges. | Drain the engine oil and fill it with fresh oil. Use an SAE30 or 10W-30 oil in most conditions. You may have to use a different viscosity in very warm conditions. |
| Low engine oil level | Low oil reduces lubrication causing internal engine friction and heat. | Drain the fuel tank. Refill with a fresh gas with an additive to clean the fuel system and stabilize the fuel. |
| Plugged engine cooling fins | Engine cooling fins are used to push air around the cylinder heads and engine block to keep it cool. | Remove the carburetor and clean it to remove deposits that m |
| MIssing engine guard | Engine guard help keep air circulating around the engine instead of allowing the air to escape the area. | Replace a missing engine guard. Securely attach a loose guard. |
| Plugged air filter | The engine works harder when it is searching for clean air. | Replace a dirty air filter. |
| Plugged mower deck | The engine works harder to turn blades through a deck packed with grass clippings. | Scrape the mower deck to remove grass clippings and debris. |
| Dull mower blades | Dull blades magnify the problem of a plugged mower deck. | Sharpen dull mower blades. Replace worn blades. |
| Overworking the engine | Operating the mower at too fast of a speed for the mowing conditions can cause the engine to overload and overheat. | Slow down the ground speed to match the mowing conditions. Avoid cutting wet grass. Double or triple-cut an overgrown lawn. |
