Kubota Z251 – Specs, Problems, Prices, Reviews

Kubota Z251

The Kubota Z251 is a Zero Turn Mower , first manufactured by Kubota in Approx 2019, and still in production today. It has proved highly popular, and still has a significant user base today.

It had a 25 hp engine, a mower deck of 54 inches, and hydrostatic transmission.

The Kubota Z251 is specifically designed for homeowners. It has exclusive easy to use features and combines comfort, convenience and style with a highly effecient mower that has both a powerful engine, and a rugged transmission. It is both easy to operate and fun to drive, but has precision mowing capabilities designed for the most demanding of jobs.

Kubota Z251 Specs

When checking specs for the Kubota Z251, it should be remembered that these can all vary slightly, depending on the year made, make and model, also if any modifications have been made, if buying a used zero turn.

All information provided on this page is deemed to be as accurate as possible, but confirmation of any information referred to here should be checked with the manufacturer before buying any model, or undertaking any repair or servicing of any Kubota mower.

Below are the main areas to check, ideally with Kubota iself, either on its main website, or with a Kubota dealership.

Kubota Z251 Production

  • Year and location, potentailly grey market

Kubota Z251 Engine

  • Size in terms of CC
  • Power in terms of Horsepower
  • Cylinders, Number and Type
  • Fuel – Capacity, Diesel or Gas
  • Liquid Cooled ?
  • Type of Starter and Starter Voltage
  • Displacement
  • Bore stroke

Kubota Z251 Mower Deck

  • Mower Lift System
  • Mower Deck Type
  • Deck Depth
  • Belt Type
  • Deck steel Thickness
  • Anti Scalp Roller
  • Cutting Width of Mower
  • Number of Blades
  • Cutting Height
  • Mower Mounting System
  • Blade Tip speed

Kubota Z251  Transmission

  • Type of Power System – Hydrostatic or Other
  • Type and Speed of Gear System

Kubota Z251  Dimensions

The dimensions of a Zero Turn Mower are really important from a practical point of view, and are detailed below

  • Wheelbase
  • Length
  • Width
  • Steering Wheel Height
  • ROPS Height
  • Weight
  • Front Tread
  • Rear Tread

Kubota Z251 Mechanical

  • 2 wd or 4wd
  • Type of steering System – differential power or other
  • ROPs – Fitted or not ( normally two post foldable)

Kubota Z251 PTO System

  • Independent or Other
  • Mid PTO or Other
  • Clutch Type and System

Kubota Z251 Electrical System

  • Ground
  • Charging Amps
  • Battery CCA
  • Battery Voltage

Kubota Z251 Attachments

  • Box Scrapers
  • Grading Scrapers
  • Landscape Rakes
  • Post Hole Diggers
  • Rear Blades
  • Rotary Tillers
  • Flail Mowers
  • Finishing Mowers
  • Brush Cutters

Kubota Z251 Problems

Problems can occur with any zero turn mower, either new or secondhand. Sometimes these problems are to do with defects in the machine, or with parts and sometimes they are to do with poor maintenance or simple checks and remedies.

Below are listed some of the most common problems with the Kubota Z251 zero turn mower, and some general ideas as to how these problems can normally be dealt with. Also listed are some common tractor problems, when used in conjunction with a zero turn mower.

 Z251 Zero Turn Mower won’t start

Check the following

  • Check the transmission gear shift lever. It may not be in the right position. Place the range shift lever into neutral and check the engine throttle lever is not put forward. Move the throttle half or full impulse.
  • Check and see if the battery connection is loose or corroded. Check connections and retighten it necessary
  • Check and see if the fuel shutoff valve is closed.
  • Check and see if the fuel is either stale, or at an improper fuel level. Drain the tank if necessary of all fuel and refill.
  • Check if the engine oil viscosity is correct or not, and if not completely change the oil in the tractor.there
  • Check and see if the fuel filter is plugged, and if necessary place.
  • Check if the air intake filter is plugged, and if it is clean or if necessary replace the air filter elements.
  • Check to see if any of the fuses have blown and if necessary replace one or all of them.
  • the engine will not start if no one is sitting in the operators seat
  • check that the parking brake lever is in the proper position
  • check the PTO switches in the proper position
  • check the motion control levers are in the proper position
  • check the key switch is in the proper position

Zero Turn Mower Troubleshooting

Blade does not rotate

Check the following

  • check PTO system is normal, replace broken mower belt
  • check if PTO system is malfunctioning

Mower belt slipping

Check the following

  • replace tension spring
  • replace warm mower belt
  • unplugs and clean mower deck
  • clean debris out of any pulley

Discharge chute plugged

Check the following

  • grass is too wet
  • grass is too long
  • cutting height is too low
  • engine RPM is too low
  • ground speed too fast

Streaking of grass uncut

Check the following

  • ground speed too fast
  • engine rpm too low
  • blades dull or damaged
  • grass too long
  • debris in mower deck

Uneven cut

Check the following

  • mower does not level
  • grand speed too fast
  • Blades dull
  • Blades worn or damaged
  • low tire inflation
  • anti-scalp rollers not adjusted correctly
  • wheels pressure not adjusted correctly

Blades scalping grass

Check the following

  • cutting height to low
  • turning speed too fast
  • ridges in terrain
  • rough or and even terrain
  • anti-scalp rollers not adjusted correctly
  • Bent blades

Excessive vibration

Check the following

  • debris on mower deck or in pulleys
  • damaged mower belt
  • damaged pulleys
  • pulleys out of alignment
  • blades out of balance

Mower loads down machine

Check the following

  • engine rpm to low
  • ground speed too fast
  • debris wrapped around mower spindles
  • front deck to low

 Z251 Zero Turn Mower won’t start, just clicks

Check the following

  • Could be potential battery issues. Check that all the motor and battery connections are clean and tight.
  • Check the battery voltage and its holding power and replace it necessary.

 Z251 Tractor / Zero Turn Mower cranks but will not start

  • The fuel may not be getting to the cylinder. check the fuel level, the shutoff valve and the fuel filter.
  • Check the air filter. It may be too cold for the cylinder to combust mixture of air and fuel.
  • Move the throttle back to idle and then half throttle and attempt to restart

Starting diesel engines in cold weather

  • Use proper seasonal diesel blends. Winter blends have certain additives to ensure that they remain liquid when it is cold.
  • Watch and check for bio diesel percentages
  • idle the engines for a time before using, this increases its efficiency and range.
  • Maintain the cooling system properly. Check the overall level and quality of coolant.
  • Use various engine starting aids if necessary. Some of the most common are glow plugs, intake preheaters and block heaters.
  • if the engine fails to start, this could be due to the cold start system malfunctioning, the fuel injectors may be dirty or there may be a faulty switch.

 Z251 Engine problems.

Either the engine went start, or it is hard to start or start and then stalls. Check the following :

  • There may be no fuel flow. check the tank, hoses, feel shutoff valve and fuel filter. Make sure they are all functioning properly and that there are no leaks from any of them.
  • The exhaust smoke may be black. This may be due to too much oil, a clogged air filter or dirty fuel.
  • The exhaust smoke may be blue or white. This may be due to fuel inside the muffler, a clogged fuel injection nozzle, poor quality fuel, a defective thermostat or that may be sediment in the fuel which may also be stale.

 Z251 Engine may be overheating.

Check the following

  • The engine may be overloaded, in human terms too much may be asked of it. Lighten the load or shift to a lower gear
  • The coolant level may be low check and see if it needs refilling and also check the hoses and radiator to make sure there are no links or loose connections.
  • There may be a blockage in the coolant system that is affecting its flow. Best thing to do is to completely flush the whole coolant system and replace as necessary.
  • The fan belt may be loose or damaged. It should be easy to check for wear and tear and any tension and replace as necessary.
  • The radiator core or screens and dirty and simply cleaning them maybe enough to solve the problem.

 Z251 Steering issues

Normally the steering either feels a bit loose or maple to one side.

  • Check the steering fluid. Check the hydraulic oil level, and check for any leaks.
  • Tires may be a bit low or flat. Check for low tire pressure and reinflate all replaced if needed.
  • The steering linkage may be in need of lubrication.
  • If there is too much play in the steering wheel, and none of the above again difference them advice and assistance should be sought from the nearest Kubota dealership, as this could be a real safety concern.

 Z251 Troubleshooting

The manual for the Kubota Z251 is likely to have a section entitled troubleshooting or something similar. This information is also often found on a number of major websites either entitled troubleshooting, resources or FAQ.

It’s mainly contains questions and answers on common problems and questions relating to Kubota machines generally can be a really useful source of advice.

Below are some of the main areas that are covered :

  • How to obtain replacement owners manual or parts catalogue
  • Free start-up checks. This can include removing debris from surrounding areas, checking oil levels and using fresh fuel.
  • Follow all safety recommendations
  • A recommended maintenance schedule
  • How to change oil
  • How to clean machine
  • How to find the right spark plug
  • How to lubricate gears
  • How to maintain pistons and cylinders
  • How to maintain air filters
  • How to store when not in use
  • Tire maintenance
  • Which attachments are available
  • How to obtain a wiring diagram
  • Tracking adjustment if machine is putting to one side
  • Type of fuel
  • Warranty information, normally the type of coverage available depending if manufacturer or dealership warranty, and the length of the warranty as well.
  • PTO problems
  • Loader problems
  • Steering box issues
  • Starting problems
  • How to fix attachments
  • Optional extras as listed below
  • Engine block heater
  • Work lights, front and rear enabling high visibility at night
  • Back buzzer
  • Toolbox
  • Horn
  • Double acting remote hydraulic control valve
  • Three point hitch
  • Drawbar
  • Top and filter kit

Kubota Z251 maintenance and servicing

One of the best ways to prevent a lot of common problems is to make sure that the zero turn mower Z251 is regularly serviced, and all the recommended checks are carried out in accordance with the schedule laid out in the sservice manual.

Check the owners service and parts manual for full details

  • Check all the service intervals. These are normally something like daily checks every 50 hours, every 100 hours, every 200 hours, every 400 hours, every 800 hours, every 15:00 hours, every 3000 hours, every one year, every two years and service as required.
  • Maintenance of loader, including daily checks, lubrication and tire inflation.
  • How best to store mower, in terms of inside/outside, draining of fuel, maintenance of battery and electrical systems etc.

Kubota Z251 and Biodiesel fuels.

Many people like to use bio diesel fuels in their Kubota Z251, but it is an area that is slightly complicated. Anyone wanting to use this type of fuel should look into it carefully, check the nature of biodiesel fuels, check manufacturers advice on whether or not to use it into engines and check potential problems it may cause. Below is a list of some of the things to consider.

  • What is bio diesel
  • Is it safe to use bio diesel in Z251 engines – check with the manufacturer
  • What are the advantages of bio diesel
  • Bio diesel fuel storage guidelines
  • How does using bio diesel fuel affect the engine warranty
  • Potential drawbacks to using bio diesel fuel
  • Cold weather flow degradation
  • Stability and storage issues
  • possible filter restriction and plugging
  • possible fuel leakage through seals and hoses
  • possible reduction of service life of engine components
  • possible coaching/block injector nozzles
  • possible crankcase oil pollution
  • potential corrosion of fuel injection system
  • possible seizure of internal components
  • possible formation of sludge and sediments
  • possible thermal oxidation of fuel at elevated temperatures
  • possible steel and gasket material degradation
  • possible compatibility issues with other materials used in fuel handling distribution and storage equipment
  • possible reduction in water separator efficiency
  • potential high acid levels within fuel system
  • potential damage to paint is exposed to bio diesel
  • emissions – check engine year of manufacture
  • emissions – how to find engine emissions certificates
  • emissions – check engines horsepower rating.

Buying a second-hand Kubota Z251 checklist

Many problems arise with a Kubota Z251 when it is brought second-hand. Below is a checklist of things to look out for when buying a used second-hand machine which if followed, may help to alleviate some of the more common problems.

  • Check vehicle documents and service book, warranty documents, year of manufacture, any chassis number and any outstanding finance.
  • Check tires and wheels for wear and tear. Make sure the tires are the same type on any one axle, check for rim damage and check we’ll attachment for weights
  • Check gearbox, especially if any grinding noises during steering. Check differential lock engages and disengages, functional rear and front power takeoff, PTO shaft condition and any unusual noises.
  • Check lifting mechanism, the hydraulic pump system, any hoses and cylinders
  • Check all electrical systems, make sure it is a functional lighting system and test all electrical elements
  • Engine and battery – check for leaks in the unusual noises when starting or idling, any abnormal exhaust colouration. Check battery maintenance and emission control
  • Oils and liquids – check for any oil leaks and liquid levels, check engine oil, coolant, hydraulic oil, servo oils and gearbox
  • Cabin and visibility – condition of drivers seat, heating, ventilation and air-conditioning systems, display indicators working, front and rear windows free of damage and check windscreen wipers and mirrors are working properly.
  • Overall condition – check the signs of repairs, proof that spare parts and accessories are original, check for any corrosion or rust and any unusual alterations to paintwork.

Kubota Z251 For Sale / Prices

Prices for the Kubota Z251 will vary depending upon the model and year of manufacture. Also things such as the number of hours it has been used for, any transmission or gearbox problems that may have occurred, as well as what type of ground the zero turn has been used on.

These murders will be offered for sale on a number of different websites online, mainly used and new tractor websites, as well as lawn and garden machinery sale sites.

In addition, these zero time mowers can often be found on sites such as craigslist and eBay. The best advice is to the purchase of these mowers in the same way when buying a used or second-hand vehicle such as a car or a truck

Kubota Z251 Reviews

There are numerous reviews available online for the Kubota Z251, which if used sensibly provide a useful basis for whether or not to purchase one, or how to deal with any specific problems that may arise. The key is to separate out the different types of reviews, and use each one appropriately.

You Tube reviews are quite often done either by dealerships, manufacturer or enthusiast users. They tend to show the mower at its best, which can give a good indication of how it should perform.

Discussion forums, such as tractorbynet, where a number of specific issues can be addressed. On the whole, users tend to be well informed, have a lot of practical experience of this type ofzero turn, and are generally willing to be as helpful as they can be.

Some discussion groups can get a bit focused on an individuals gripe if they have had a really bad experience, either with the Kubota Z251 itself, or a particular dealership.

Consumer reports tend to be done by independent review body’s, and are normally fairly reliable and reasonably objective.

It is worth checking the credentials of the person doing the review, and whether or not taken into account all the relevant factors affecting individual judgement concerning the use of the mower.


Kubota Z251 Oil Capacity,

Kubota Z251 Blades,

Kubota Z251 Oil Filter,

Kubota Z251 Wiring Diagram,

Kubota Z251 Fuel Pump,

Kubota Z251 Transmission Kit,

Kubota Z251 Diesel,

Kubota Z251 Hydraulic Pump,

Kubota Z251 Battery,

Kubota Z251 Hydro Rebuild,

Kubota Z251 Transmission Failures,

Kubota Z251 Gearbox Problems,

Kubota Z251 Fuel Solenoid,

Kubota Z251 Starter and Operating Problems.