Kubota Tractor Won t Start: Causes and Effective Repairs

Your Kubota tractor wont start because of a flat battery or other causes. Although other problems can also lead to such a situation, it usually requires a new battery.

Kubota Tractor Wont Start

This article will take you through all the reasons behind a Kubota tractor that will not start and suggest effective methods to repair it.

Why Is Your Kubota Tractor Clicking but Not Starting?

Your Kubota tractor is clicking but not starting because of poor battery connections or a dead battery. It can also happen because of a binding cranking motor or faulty solenoid. Additionally, a problem with the ignition switch, control unit, or valve lash can be the cause.

  • Defective Battery Cables or Flat Battery

Your Kubota tractor will not start if the battery is dead or has defective connections. Having bad connections is a common problem with vehicles. It prevents power transfer from the battery to other components due to dirty, loose, or impaired cables.

If you notice white crystals around the battery terminals, you have dirty connections. These chalky substances develop due to battery acid around the poles and prevent power transfer. Observe positive and negative terminals for signs of build-up.

The tractor vibrates a great deal, leading to the displacement of cables and loose connections. You can prevent it by regularly inspecting the connections and servicing the tractor. In some cases, the cables wear out due to corrosion or mice.

You can also look for leakage signs. Sometimes filling up the electrolyte in the battery solves the problem. Otherwise, you might have a flat battery.

Many issues can cause a run-down battery, such as:

  • Not using the tractor for a long time
  • Neglecting acid build-up for a long time
  • Three to five year old battery starts failing
  • Extremely hot or cold temperatures affecting chemical functions
  • Forgetting to turn off headlights or other electrical components

You can detect a faulty battery by using a multimeter. Connect the red pin to the positive and the black one to the negative terminal. Set it to 20V, and if the reading is less than 8V, you need a new battery.

  • Tractor Clicks Due to a Faulty Solenoid

If the tractor won’t turn over with new battery and proper connections, you can suspect an issue with the solenoid. It is a common problem in vehicles but easy and inexpensive to fix.
A starter solenoid cranks the engine when you turn the ignition key. It can develop faults if mechanically damaged, for instance, due to an impact. Electrical problems, corrosion, and overheating are other reasons for solenoid failure.

You can locate and test the starter solenoid. It is easy to locate in most cars, while others need effort. You can look for it under the hood, near the gas tank, or beneath the rear wheel or seat.

You can also track the red cables from the battery to locate it or consult the user manual. After finding it, use a multimeter to analyze the continuity. While you are at it, observe the terminals and wires for signs of corrosion.

  • Bad Tractor Ignition Control

Another reason why the Kubota tractor does not work yet it clicks is a bad ignition control switch. If it has damaged connections, you will also hear the clicking noise.

The switch can fail due to the following reasons:

  • Connecting multiple devices to the switch
  • Mishandling or impact as a result of an accident
  • Collection of dirt or dust particles inside the switch

You can easily detect a non-functioning ignition control switch. You can either test it by wiggling the connections or using a multimeter. Wiggle the wires behind the switch as you try to start the engine. If moving the wires makes a difference, or if they are corroded, you will only need to replace them.

  • Damaged or Binding Starter Motor

A damaged or binding motor can result in Kubota zero turn clicks but won’t start. The motor may fail due to electrical issues such as worn brushes or wires or mechanical wear of bearings. These matters do not let the tractor start and produce a clicking sound.

Causes of Tractor Not Starting

You can test it by connecting a multimeter set at 12V. First, check the tractor’s manual to know if the motor and solenoid exist separately or as a unit. Most tractors have separate, and the solenoid is attached to the body under the hood.

A damaged motor can also bind to the flywheel, locking the motor and tractor engine. When it binds and you turn the key, you will hear clicking.

You can diagnose a binding motor by turning the engine anti-clockwise. You can do it with your hand, but if the flywheel is covered, you can turn the crankshaft from below with a ratchet. If the anti-clockwise motion releases the motor, you have a binding starter.

  • Tractor Valve Lash Out of Specification

If your Kubota tractor turns over but won’t start, the valve lash might be beyond specification. The tractor engine has valves that control fuel and air input to the combustion chamber. These valves should open and close with a specific gap, but due to damage, a larger gap creates problems.

Normal valve lash enables the engine to crank at a speed that is good for the engine’s function. However, an out-of-spec lash causes the late opening and high gas pressure in the cylinder. It then leads to the clicking sound.

You can test for inaccurate lash by turning the engine with your hand. Put it on the flywheel and turn it clockwise. If there is a hindrance, you have an out-of-spec valve lash.

  • Faulty Tractor Control Module

The latest Kubota tractors have control modules. These modules receive alerts from various sensors to control vehicle functions. The module usually controls the processes inside the engine or transmission, but a Kubota tractor won’t turn over if it develops a fault.

You can test the module connections by wiggling the wires. Meanwhile, try to start the engine to understand the cause. Also, scan them to find damaged or corroded connections.

  • Damaged Kubota Engine Parts

If you do not suspect the causes indicated above, the tractor engine might have defects. Many tractor engine parts can damage and prevent the tractor from starting. Some of these are expensive to repair, but total engine failure is uncommon. The engine can only fail entirely if you have been using low quantity or poor-quality oil for a long time.

Specific engine parts such as con rods, bearings, cylinder heads, spark plugs, timing belts, or fuel injectors can fail. It can also be the reason why the Kubota 3-cylinder diesel won’t start.

How To Fix a Kubota Tractor That Does Not Start but Clicks?

You can fix a Kubota tractor that does not start but clicks by cleaning the acid build-up on the tractor battery or replacing the battery. You can adjust the out-of-spec Kubota tractor valve lash so it may start working. Otherwise, fix the faulty starter motor or safety switch.

  • Clean the Kubota Tractor Battery Terminals

Cleaning the dirt or acid build-up on the battery can solve the problem. You should clean it regularly, especially if you observe dirt or build-up in these spots.

The steps below will help you clean the battery by yourself:

  1. Remove the ignition key to turn off the engine and wait for it to cool down.
  2. Use a wrench to remove the positive and negative cables from the respective terminals.
  3. If you see corroded wires, replace them.
  4. Use a solution of baking soda and water to clean the terminals. You can dissolve one tablespoon of baking soda in a cup of clean water.
  5. Use a wire brush to scrub off the build-up. Wear gloves while you clean the terminals. Once cleaned, wash the terminals with water and dry them with a clean cloth.
  6. Reconnect the cables and start the engine.
  • Replace the Dead Kubota Tractor Battery

In the case of a dead Kubota battery, only replacing it will fix the tractor. If you want a wet battery, buy the acid separately and fill it. Otherwise, you can go for a sealed battery that is already charged.

  • Adjust Kubota Tractor Valve Lash

You can also adjust the Kubota tractor’s excessive valve lash. You can turn to the vehicle’s manual for the specifications.

Follow these steps to make adjustments:

  1. Remove the valve train lid when the engine cools down.
  2. Elevate the piston in the cylinder by rotating the engine.
  3. Use a feeler gauge to inspect the gap between the valve stem and the rocker’s arm.
  4. Adjust the loose screws and nuts by using a wrench.
  5. Do the same for each cylinder by rotating the engine.
  6. After adjusting all valves, cover the valve train and test the engine.
  • Fix the Faulty Starting Motor or Solenoid

Examine the starting motor’s connections to ensure they are spotless and free of debris or dirt. You may use a wire brush to clean them. If the tractor does not work due to a dirty motor, cleaning it will fix the problem. Otherwise, you will have to take the tractor to the technician.

Fixing a Kubota Tractor


Similarly, you have to repair your tractor’s malfunctioning starter solenoid. First and foremost, check that the solenoid you purchase is the appropriate model for your tractor. You should always choose a solenoid that works with your tractor. Installation is straightforward, but you can have professionals do it for you.

  • Repair the Defective Tractor Safety Switch

If the above measures do not fix the tractor, you should locate a defective tractor shutdown switch. The common Kubota tractor safety switch locations are clutch or brake pedal, transmission, or below the seat.

You can detect the defective switch by yourself or hire a technician. Try to move the connections around the switch to locate the fault.

Replacing the Battery on Kubota

What are the potential causes of a Kubota tractor not starting?

Potential causes of a Kubota tractor not starting can be varied and complex, but identifying engagement issues is crucial. Faulty ignition switches, failing starter motors, or a drained battery could be at fault. Additionally, fuel delivery problems, such as clogged filters or a malfunctioning fuel pump, might prevent the tractor from starting. Thoroughly examining these components is essential to diagnose and resolve the issue efficiently.


After learning the reasons why the Kubota tractor won’t start just clicks, you can take steps to fix it. Before that,

check out the main findings from this article:

  • A flat battery, damaged ignition or safety control switches, and faulty solenoids can stop the tractor from starting.
  • Out-of-specification tractor valve lash and damaged engine parts can also cause similar problems.
  • You can fix the tractor by cleaning or replacing the battery, adjusting the valve lash, or replacing worn parts.

These suggestions can help you resume your farming practices as soon as you repair the tractor!

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