Kubota zero turn mowers have a reputation for being one of the best zero turn mowers you can own. This popularity has also created a well-documented list of the many problems that can affect these fantastic machines’ performance.
You’ll find all the Kubota zero turn mower problems and solutions below to help you fix your lawn mower.
8 Common Kubota zero turn mower problems
Kubota zero turn mowers are popular for their maneuverability and speed. Still, like any machine, they can experience problems such as:
- It keeps shutting off
- Starting problems
- Hydrostatic transmission problems
- Fuel problems
- Deck problems
- Electrical problems
- Not mowing properly
Keeps shutting off
Many customers have complained that their mower engine shuts down in the middle of work, especially when working in dry or dusty conditions.
This is the result of the engine overheating, which is usually caused by a blocked air filter. The air filter becomes blocked with grass clippings and dust.
This is quite easy to fix – you simply remove the filter and either brush off the debris or blow it out with an airline from a compressor.
Note: Remember to blow the dust out of the air filter from the back side of the filter so you don’t blow it into the filter paper. But, if it is very dirty it is better to replace it.
If the radiator is blocked with dust and debris or if the fan that cools the radiator is not turning, the engine may shut down due to overheating. If the thermostat in the engine is sticking closed it will not allow the water to travel through the radiator to allow it to be cooled. This will cause the engine to overheat very quickly in warm weather.
Starting problems are common on all mowers as soon as they start to get a few hours on the clock. But fortunately, there are several things you can check.
Check that your battery is fully charged and that the battery terminals are tight and not corroded.
Next, check that your tank has fuel in it and can make its way to the carburetor (petrol models) or fuel pump (diesel models) – check that the fuel filter is not blocked too.
Check your starter is working. You should hear it turning the engine over – if your engine is not turning and your battery is good, you need to fix the starter.
Many times, users have reported the starter clicking but not turning the engine over. This clicking sound is either the battery is flat or not charged enough, or the starter motor is faulty. The clicking sound is the noise made by the coil engaging the engine’s flywheel, but the motor is not turning the flywheel around.
Finally, check that your spark plug is providing a good spark and that the lead and coil which supply the spark are in good condition too.
Hydrostatic transmission problems
Although Kubota is a reputable Japanese company, they seem to have some issues with their hydrostatic transmission. Thankfully, these issues are few and far between, so it’s not a significant cause for concern.
Many users report leaks from the air breather vent in the transmission and the filler cap. If these leaks are not fixed under warranty, they can be costly to fix afterward.
The drive belt from the engine to the hydraulic pump can wear with age, which causes it to slip and reduce the machine’s performance.
Another issue affecting some models is the fan that cools the hydraulic pump can stop, which causes the hydraulic pump and the oil to overheat.
Leaking fuel lines can be an issue on older models – check the fuel line from the tank to the engine for any spits in the pipe. It will be much more apparent on diesel engines as the ground underneath the mower should show the patch on the floor where the fuel is leaking out.
For gas models, it may be harder to detect as the fuel evaporates over time – but there should still be a smell of gas in the shed where the mower is stored.
Another common complaint from Kubota zero turn mowers is that they have steering issues, the main one being that the mower pulls to the left or the right when driving.
This is usually fixed by adjusting the stop bolt for the steering handles. When the stop bolts on each side are not set equal, the wheel turns faster than the wheel on the other side.
Another issue seems to be that the steering handles are too tight to move. This can be fixed by either loosening the pivot bolts or applying lubricant to the pivot.
Sometimes selecting the deck height can be an issue. This is caused by a faulty height limit switch, which will need to be replaced.
Linkages don’t seem to give much trouble on Kubota mowers, but if you still have deck height setting problems, it will most likely stem from some type of linkage issue.
Faulty wiring can affect mowers that are stored in sheds or barns with mice or rats. These pesky rodents can chew through wires, leaving you with an issue that is not easy to find.
Sometimes faulty key switches can cause a mower not to start even though the battery is fully charged and the starter is good. You can check this by running a separate wire from the battery to the starter motor.
Other areas to check for faulty electrical are the ignition coil and spark plugs – there should be a bright blue spark when the engine is turning over. If the plug is new and the coil lead is not damaged, chances are the coil is broken and needs to be replaced.
Not mowing properly
Mower blades not correctly sharpened are the number one reason a mower is not cutting grass properly.
Dull blades also cause streaking in the lawn. Streaking is when a row of clipped grass is left behind the mower, which looks unsightly. Other causes of streaking include:
- The mower blades are not turning fast enough
- The underside of the cutting deck is clogged with grass
- The forward speed is too fast for the cutting blades.
After a season of mowing, you should remove the blades and sharpen them properly. If you don’t know how to do this, take the mower to a lawnmower repair shop, and they can do it for you. It costs very little and makes a massive improvement on how cleanly cut your lawn looks.
Common causes of Kubota zero turn mower problems
The main causes of most mower problems are either a lack of machine maintenance or operator error.
Machines are made of many different moving parts which work together to provide a system. When one system begins to wear down, it affects another system. For example, the belt which drives the hydraulic pump from the engine pulley. This part is vital in the hydraulic system. When it eventually wears down, that drive to the pump will stop, which will affect the hydraulic system.
NOTE: When you buy a machine made of so many moving, wearing parts, it is essential to check and maintain them regularly.
Faults can also arise from manufacturing issues – such as the 2019 Kubota recall due to a potential fire hazard. This was because a throttle cable made contact with internal electric wiring.
How to troubleshoot Kubota zero turn mower problems
Troubleshooting a Kubota zero turn mower can be challenging, especially if you are not familiar with the inner workings of these complex machines. However, with the proper knowledge and tools, you can often diagnose and fix common problems yourself, saving time and money on costly repairs.
To troubleshoot your Kubota zero turn mower, you will need to follow a few basic steps:
- Mower not starting: check the battery, starter, ignition wires, fuel, and ignition system.
- The mower stops running: check the air filter, spark plugs, ignition system, fuel tank, and fuel lines.
- Bad cut on grass: check the blades are sharp and check the drive belts to the blades are correct.
- The mower doesn’t move: if the engine runs but the mower doesn’t move, check the drive belt and transmission.
- The mower is overheating: mowers will overheat if the engine is low in oil, the radiator is low in water, if the radiator fins are blocked or if the fan is broken.
- Bad traction: sometimes, if the tires are at different pressures, it causes problems with traction – check the pressures are correct on all four wheels.
Attention: Driving a mower on sloping ground is very dangerous if the tire pressures are not correct – the mower could overturn.
Although I have listed a large number of faults or issues associated with the Kubota zero turn mowers, they still have one of the best reputations for durable, high-quality machines. Many Kubota zero turn mower owners would never buy another brand.
Check the fuel system, transmission system, cutting deck system, starter system, and cooling system on a regular basis for trouble-free operation.