14 Causes of a Deadly Start in a Kubota Zero Turn: FIXED

You’re in the middle of cutting the grass when the mower starts to splutter and die. I have compiled a comprehensive list of potential causes and solutions to assist you quickly diagnose the issue and get your mower back up and running.

If the fuel system is impeded by things like old gas, a blocked fuel filter, a clogged fuel line, a defective fuel pump, a dirty carburetor, or a plugged gas cap, your Kubota zero-turn will start but quickly die.

A clogged mower deck, low oil level, dirty spark plugs, a broken ignition coil, a blocked air filter, the improper choke setting, and a clogged air filter are additional potential causes of death.

Always observe the safety measures outlined in your Kubota’s manual. It’s not safe to work on a car without first removing the ignition key and the wires from the spark plugs.

kubota zero turn

Before diagnosing, repairing, or operating, be sure you’ve read and fully understood any relevant safety information found in the equipment’s operator’s manual. If you lack the expertise, experience, or physical ability to complete the repair safely, you should seek the advice of a professional.

Causes of a Kubota Zero Turn’s Failure to Start, Run, or Die

Using Old or Corrupt Fuel in a Kubota Zero Turn Mower

You can usually trace a mower’s poor performance, sputtering, and eventual death back to fuel that’s gotten stale. This is due to the fact that gas might lose some of its effectiveness as early as a month after purchasing.

Most modern gas contains ethanol, which is a moisture magnet for the fuel system. This ethanol and water solution will eventually settle to the bottom of the gas tank. The engine gets very hot with this mixture.

The ethanol and water are corrosive, and they leave behind varnish and sticky deposits that adhere to fuel components and reduce gasoline flow. If there isn’t enough gas, the motor can die.

Your Kubota zero-turn may face a fuel limitation, resulting in poor performance and eventual death, if this occurs.

SUGGESTION: Make sure there is gas in the tank. You should empty the fuel tank if it has sat there for longer than 30 days.

Never use old gas in the mower. For optimal performance, Kubota zero-turn mowers need unleaded gasoline with an octane value of 87 and no more than 10% ethanol. Here you may learn more about which gas is best for your Kubota mower.

A fuel additive, such as Sea Foam Motor Treatment, can keep gas stable, remove moisture, and clean the fuel system before it is added to the tank.

To learn more about the benefits of using sea foam as a fuel stabilizer in a lawn mower, check out the article.

Put the combined gas and additive into the gas tank. Turn the zero-turn mower on and let it run for about 15 minutes to distribute the mixture throughout the mower.

Kubota Zero Turn Mower Fuel Filter Clogged

Your Kubota zero-turn mower has a gasoline filter inline made of polypropylene. When fuel is pumped from the tank, it is filtered through this device to remove debris and other pollutants before they can enter the engine.

If you don’t frequently replace your fuel filter, dirt can build up and eventually stop the engine from running.

Substitute a brand-new gasoline filter for an old one if it has become clogged. Make sure the arrow on the side of the filter housing points in the direction of fuel flow before installing the filter.

Kubota Zero Turn Mower Fuel Line Blockage

The accumulation of debris in the system is a direct result of using outdated gasoline. If the gasoline line gets clogged up with the sticky substance, it will get harder to pump fuel through.

If your Kubota zero-turn isn’t getting enough gasoline because the pipe is clogged, it may die.

SOLUTION: Turn on and off fuel flow at the fuel shut-off valve to look for obstructions in the fuel lines.

If a clog is found in a fuel line, the fuel supply must be shut off and the line must be disconnected from the zero-turn.

Fuel lines can be cleaned by spraying carburetor cleaning into them. In order to unclog, do this. After that, you should blow compressed air through the line to clear it.

If the fuel line is blocked and cannot be opened, a new fuel line of the same length and diameter must be installed. Activate the gasoline system.

Kubota Zero Turn Mower Fuel Pump Failure

The vast majority of Kubota tractors with a zero-turn radius employ a vacuum pump. It operates by sucking gas from the tank and pumping it through the engine’s exhaust system into the carburetor. Using a gasoline pump on stale fuel will eventually cause it to break down.

Checking fuel flow through the fuel line is the ANSWER to figuring out if the fuel pump is broken. This might have been accomplished in the previous step.

Next, make sure the fuel pump is releasing fuel. Stop the fuel flow and take the fuel line off the carburetor. After stowing the line in a holding tank, you can activate the fuel flow and begin the zero-turn.

Keep an eye on the gasoline line to see if there is a continuous or pulsing flow coming out. If the fuel flow is insufficient, a new fuel pump should be installed.

A Kubota Zero Turn Mower with a Filthy Carburetor

The carburetor controls the ratio of fuel to air for combustion, allowing the engine to keep operating. An aged gas supply is a common cause of carburetor malfunction.

Old gas’s varnish residue can clog fuel lines and stick moving components. There won’t be enough gas for your Kubota engine to keep going.

These quick tests will help you establish if the problem is with your carburetor before you take it apart to clean it.

  • Be sure the carburetor is receiving fuel. If you’ve been monitoring the gasoline pressure at the tank, you should have already known this.
  • Take off the air filter from the housing.
  • Start your mower after spraying carburetor cleaner into the air intake.
  • The issue may lie in the carburetor if the Kubota fires up, runs smoothly for a while, and then dies.

The problem can be fixed by disabling the Kubota zero-carburetor. turn’s Cleaning the carburetor requires disassembly. If you need guidance on how to clean a carburetor, read this page.

If you’d rather have someone else fix your lawnmower, you can bring it to a store that specializes in fixing small engines.

Kubota Zero Turn Mower Air Filter Clogged

Protecting the engine from dirt contamination is the air filter’s primary function. It prevents material like dirt and dust from entering the air intake and damaging the motor.

If the air filter on your Kubota zero-turn is clogged, the engine will be deprived of air and eventually stop working. Overheating could cause it to shut off.

The air filter should therefore be maintained in excellent condition at all times. The air filter should be changed annually and cleaned multiple times throughout the mowing season.

When using the mower more frequently than the typical homeowner or in extremely dusty conditions, this should be done more frequently.


This is how you clean the paper air filter in your Kubota zero-turn tractor:

  • Take the paper element out of the air filter housing. Take care that dust doesn’t get sucked into the fan.
  • Use a clean, dry cloth to remove any leftover dust or grime from the housing.
  • Knock out as much grime as you can from the filter by tapping it against a hard surface. Compressed air should be avoided since it can ruin the paper component.
  • Raise the filter to the light. If the paper element is broken, oily, or otherwise blocking light, you should get a replacement filter. It can be used again if it lets light through and is otherwise in good condition.
  • Make sure the air filter is in place and the filter housing cover is back on.

Kubota Zero Turn Mower with Blocked Engine Cooling Fins

With prolonged use, the Kubota’s engine may overheat and shut down, rendering your mower useless. Clogged engine cooling fins are a common cause of overheating.

The fins’ ability to direct airflow around the engine block and cylinder head relies on keeping them free of dust and other debris.

The solution is to clean the cooling fins and replace any that are broken. The engine block and the area around the shroud should be cleaned of any dirt.

You may improve airflow by installing your heat shield properly.

Kubota Zero Turn Mower’s Engine Oil Gets Low

The engine oil level in your Kubota zero-turn should be checked before each use. Many people who use lawn mowers don’t do this. It doesn’t take long at all to quickly inspect the engine oil with the dipstick.

Avoiding expensive repairs by discovering a low engine level is possible. Overheating and shutting down can occur if you run your zero-turn mower with the engine oil level too low.

Because of increased friction caused by contact between moving engine elements, the crankcase will overheat if there isn’t enough engine oil to lubricate the engine. Because of the extreme heat, the engine oil and other components may start to burn.

To solve the problem of your lawnmower shutting off due to low engine oil, you can try to fix the level by adding more oil.

Because the Kubota stopped down because of a lack of lubrication, a simple solution like adding additional engine oil is usually ineffective.

Severe engine damage was probably the result. In order to assess the level of damage sustained by your mower, a qualified expert in small engine repair should examine it.

Your local Kubota service facility or an engine dealer service center is a suitable choice for engine maintenance and inspections on your zero-turn. It could be an engine made by Kawasaki, Kohler, or some other company.

Kubota Zero Turn Mower Engine Needs More Oil

Your zero-turn can die from either not having enough engine oil or having too much oil.

The crankcase pressure will increase if there is too much oil. Find out more about what happens when you use too much oil in your engine here.

If you check your engine oil and find that the level is excessively high, the solution is to drain off some of the oil.

A turkey baster or oil evacuator can be used to remove oil from the drain cap, the oil filter, or the oil fill area. To fix the engine oil level, keep draining and refilling it.

Unclean Spark Plug or Loose Connections on a Kubota Zero Turn Mower

If your Kubota zero-turn is suddenly not working, check the spark plug. A dirty or damaged spark plug could be the cause of your mower not starting.

The electrode gap must also be checked and adjusted so that it complies with the manufacturer’s specifications. A sluggish or dead mower could also be the result of spark plug wires that are too loose.

If your spark plug is dirty, the solution is to take it out and clean it. A new spark plug should be put in if the old one is broken or has a particularly dark color.

Also, double check that the spark plug wires are properly attached and the spacing is set per the engine manufacturer’s recommendations.

Kubota Zero Turn Mower Ignition Coil Problem

When your mower gets heated, the ignition coil’s winding can become dislodged and cause a short. Causes the spark plugs to be deprived of the voltage they require to spark.

After a time of use, this can cause your mower to stop working.

Use an ohmmeter to check for a break in continuity and pinpoint the faulty ignition coil. If you detect a crack in the ignition coil, you’ll need to get a new one.

Kubota Zero-Turn Mower Has a Misplaced Choke

By reducing the amount of air flowing into the carburetor, the choke on your Kubota zero-turn increases the concentration of gasoline entering the combustion chamber.

When the engine is cold, you can’t start it without this. When the engine temperature rises, more air is required to keep the zero-turn going, so if you forget to turn off the choke, the engine will die.

CURE: Check the placement of your choke lever. To start a cold engine, you need to turn the throttle to the closed position. Once the engine is up to operating temperature, you can turn the choke to the open position.

Kubota Zero Turn Tractor Leaks Gas Due to a Faulty Gas Cap

The gas cap is perforated to permit airflow. This will allow air to escape from the gas tank. If the fuel tank’s vent cap stops functioning, the tank will become vacuumed and refuse to release its contents.

Whilst your Kubota zero-turn could have started out with a faulty gas cap, it will eventually turn off once a certain amount of time has passed. This is due to the fact that if air is prevented from entering the tank, a vacuum will develop inside.

To test if the gasoline cap is the source of the problem, you can try letting some air into the tank by loosening the cap.

If it does, secure the cap and try running the mower for a bit to see if it again begins to run slowly or shuts off unexpectedly.

It’s important to change a faulty gas cap.

Kubota Zero Turn with a Plugged Mower Deck

If the deck of your mower gets clogged up, the engine has to work harder, gets too hot, and eventually cuts out.

When grass accumulates under the mower deck, the engine has to work harder to spin the blades through the muck. Worsening the issue can be dull mower blades.

One way to solve this problem is to regularly sharpen the mower blades and scrape the mower deck. Maintaining a clean mower deck and sharp blades not only makes for a more efficient engine, but also produces a cleaner cut.

The deck’s blades and the space beneath it provide air flow, which lifts and cuts the grass.

Why Won’t My Kubota Zero Turn Mower’s Batteries Charge?

Keep the engine speed high while operating the zero-turn. Don’t leave your mower idling for too long. To charge your battery, you need to use the engine’s power.

See the article “5 Things That Are Draining Your Battery” for a rundown of potential culprits.

You may have an issue with the charging system if you find yourself constantly recharging the battery while ensuring the battery and cables are in good condition and properly linked.

In this article, I’ll go over some things you can do to make sure your battery and charging system are in good working order. If any of these tests reveal that your battery is defective, it should be replaced.

If you discover that your vehicle’s charging system is malfunctioning, it is imperative that you have a professional mechanic inspect and fix the issue.

It’s easy to throw parts at the charging system in the hopes of fixing the problem if you don’t know anything about the charging system.

Electronic components are often pricey and non-returnable due to their nature.