The Kubota Lawn Mower Would Not Start Without the Choke Engaged

If you don’t keep the choke on while the mower is going, it will start, but it won’t continue running. Figuring out what caused the problem and repairing it will make your engine run better.

If the engine of a Kubota lawn mower is receiving either too much air or not enough fuel, it will be the only time it will run with the choke engaged.

This might be the result of a filthy carburetor, stale gas, a clogged fuel filter, a malfunctioning fuel pump, a defective gas cap, a blocked or pierced fuel line, or a damaged carburetor gasket.

Please refer to the operator’s handbook that came with your Kubota for any and all safety concerns. Before beginning any repairs, it is necessary to take precautions such as removing the ignition key and the spark plug boot.

The following are some of the reasons why your Kubota lawn mower will only operate with the choke engaged:

  • Due to a lack of gasoline
    • Used fuel
    • An unclean carburetor
    • Clogged fuel line
    • Defective fuel pump
    • Blocked fuel filter
    • Defective fuel cap
  • A surplus of air
    • Defective carburetor gasket
    • Puncture in the fuel line
outdoorstip kubota Lawn Mower

7 Explanations for Why a Kubota Lawnmower Won’t Start Until the Choke Is Engaged

1. Using Stale Gas in a Kubota Lawnmower

It’s possible that fuel constraints will need you to use the choke on your Kubota mower in order to keep it going. This is done to limit the amount of air that can pass through so that the requisite air-to-fuel ratio may be achieved for combustion.

The majority of fuel limits may be traced back to stale gas. As soon as 30 days after purchase, the quality of gas might start to deteriorate.

Ethanol, which is now contained in the majority of gasoline, is known to draw moisture from the surrounding air. This combination of ethanol and water not only leaves varnish behind, which covers the fuel system and causes fuel limitations, but it is also harmful to the fuel system and the engine.

Mowers manufactured by Kubota must be fueled with unleaded gasoline that has an octane value of at least 87 and contains no more than 10% ethanol. Never run your vehicle on gas that has more than 10% ethanol in it.

You may learn more about how to choose the correct gas for your Kubota mower by reading the information provided below.

SOLUTION: Remove any stale gas from the tank before driving. To assist in cleaning and reducing the amount of moisture in the fuel system, add new gas to the tank along with a fuel additive such as Sea Foam Motor Treatment or STA-BIL.

It will also maintain the gas’s stability, allowing it to remain intact for a longer period of time before it begins to degrade. Have a look at the reasons why I prefer to put Sea Foam in every one of my little engines.

Turn on the engine of your Kubota, let it run for a while, and give the treated gasoline some time to make its way through the fuel system.

It’s possible that your engine will start running more smoothly and could even keep going even if you don’t have the choke engaged. In the event that it does not, proceed to examine the things that are listed below.

2. A Kubota Lawnmower with an Unclean Carburetor

In order to control the proportion of fuel to air that is introduced during the combustion process, a Kubota carburetor is used. As it becomes filthy, probably because of old gas, the fuel pathways and internal components might get clogged and stop working properly. This can happen for a number of reasons.

In order for the engine to get the appropriate quantity of gasoline and function properly, the carburetor will need to be either cleaned or changed.

SOLUTION: If you are somewhat mechanically inclined and don’t mind dealing with tiny components, you should be able to remove and clean the Kubota mower carburetor on your own by following the directions in this article.

If following these methods to clean the carburetor doesn’t immediately result in it functioning properly, you may need to either rebuild it or replace it. If you don’t feel like doing the task on your own, you may have a technician that specializes in working on tiny engines clean or repair the carburetor for you.

3.With a Kubota Lawn Mower, there is either a Puncture or a Clog in the Fuel Line.

If the gasoline line becomes punctured, it might allow air to be sucked into the line, which would then cause the engine to receive an excessive amount of air. Alternatively, there is the possibility that a clog may form in the line, which would reduce the quantity of gasoline that is supplied to the engine.

It’s possible that one of these problems is what’s causing the mower to refuse to run until the choke is engaged. Adjusting the amount of air that enters the engine via the choke is necessary in order to maintain the correct fuel-to-air ratio that is necessary for combustion.

SOLUTION: Examine the gasoline lines carefully. Follow the line that is emerging from the gasoline line, and then follow that line all the way up to the carburetor. Examine the fuel system for any holes, punctures, or fractures that could allow air to enter.

Next, examine the gasoline line for any obstructions that could be preventing fuel from flowing freely. Then, use the fuel shut-off valve to stop the flow of fuel via the fuel system. The next step is to cut off the end of a segment of the gasoline line and put it in a container specifically designed for fuel collection.

After turning the fuel flow back on, check to ensure that a sufficient amount of fuel is entering the container from the fuel line. Turn off the gasoline supply and disconnect the fuel line from your mower if you are not receiving a sufficient amount of flow.

In order to break up the blockage, spray some carburetor cleaning into the pipe. After this, you should use compressed air to remove the obstruction. That is vital to repeat.

If you simply are unable to get the fuel line clean and the clog cleared, or if you discover a puncture in the fuel line, you will need to replace that piece of the fuel line with a new section of the fuel line that has the same diameter.

4. A Kubota Lawnmower That Has A Clogged Fuel Filter

To filter the fuel as it is pumped from the fuel tank into the engine, an inline fuel filter is installed between the fuel lines. This is done so that dirt and other pollutants that might cause wear on the fuel tank are prevented from entering.

This is a component that has to be updated on a yearly basis in order to maintain it in excellent shape. As it gets clogged, it may limit the quantity of fuel that is able to travel through the filter, which may be an inconvenience.

SOLUTION: After removing a filter that has become clogged with debris, install a new inline fuel filter between the fuel lines.

On one of the housing sides of the filter, you should locate an arrow. It is necessary to install the filter in such a way that the arrow points in the same direction as the gasoline flow.

5. A Kubota Lawnmower with a Defective Fuel Pump

In order to transfer gasoline uphill to the carburetor on your Kubota mower, you will need to utilize a fuel pump. The majority of Kubota mowers are equipped with a vacuum pump. The gasoline is moved from the fuel tank to the carburetor by a pump of this sort, which makes advantage of the vacuum created by the engine.

In order to test the fuel pump, you will first need to ensure that fuel is being supplied to the pump’s input port. The next step is to detach the fuel line from the carburetor and put it in a container large enough to collect gasoline while you test the flow of fuel flowing out of the line.

SOLUTION : Replace the fuel pump with a brand-new one if you discover any cracks or gasoline leaks, or if the fuel flow is insufficient for the needs of the vehicle.

6. A Kubota Lawnmower with a Defective Carburetor Gasket

The gasket that lies beneath the Kubota carburetor is susceptible to wear and tear, which may cause it to degrade to the point where it no longer seals. Because of a faulty gasket, excess air may be pulled into the system, which would cause the engine to operate in a lean state.

When an engine is said to be running lean, there is a greater concentration of air and a lower fuel concentration than is needed by the engine. Because of the faulty gasket, you will need to make use of the choke in order to compensate for the additional air that is being drawn into the engine.

Carry out an inspection of the carburetor and check to see that all of the bolts are secured firmly and that the gasket is in excellent shape.

SOLUTION: If you notice that the gasket is no longer effective at sealing, you will need to obtain access to the carburetor and gently remove the linkages and bolts that are attaching it. Take the carburetor and the gasket off of the engine.

Replace the old gasket with a brand-new one, then rejoin the carburetor, the bolt, and the linkages. When you have the carburetor removed from the mower, this is also an excellent chance to identify whether or not it needs to be cleaned.

7. A Kubota Mower with a Defective Gas Cap

It is necessary for the gasoline tank to have a vent that enables air to enter the tank. When the vent is blocked and air is prevented from entering the fuel tank, a vacuum will develop within the tank. Because of the vacuum, the gasoline won’t be able to reach the carburetor.

The gas cap serves as the vent for the fuel tank. If you want to determine whether or not there is a vacuum buildup, you may use a pressure gauge, or if you don’t have a gauge, you can follow these procedures instead:

  • Turn the cap on the gas tank counterclockwise to let air in.
  • Make sure the choke is turned all the way off.
  • If the engine continues to run without the choke being in the on position, the fault may be with the cap.
  • Make an effort to reproduce the issue so that you can be sure the cap is faulty.
  • Pull the plug and make sure the engine is running without the choke while you tighten the cap.
  • There is a good chance that you have a faulty cap if, after a time, the engine starts to splutter and won’t run smoothly until you release the cap first.

SOLUTION: Replace a faulty gas cap.

Are you still having issues with the Kubota Lawn Mower you purchased?

If you own a lawn mower for a sufficient amount of time, you will eventually have issues with it, such as it failing to start, not continuing to run, smoking, leaking gas, producing an uneven cut, vibrating, or another problem.

In an effort to save you both time and money, I have compiled a guide that will assist you in diagnosing and resolving any issues that may arise with the Kubota mower you own.

This tutorial may be seen at the Common Kubota Lawn Mower Issues & Solutions website.

If you are unclear how to properly do diagnostics and repairs on your Kubota lawn mower, it is preferable to have a professional make the repairs instead of attempting to do them yourself.

By doing this, you will reduce the risk of injuring yourself or causing more damage to the mower. Your neighborhood Kubota dealership or lawn mower repair shop will be able to assist you in finding a solution to the issue you’re having.