Search for the parts you require either by Component (e.g. 'cooling system' parts)  or by Engine Model (eg D902 etc) from the menu above - no need for manufacturer's part numbers, engine serial numbers, family or codes.

Jem Engines has a programme of producing Reconditioned engines for stock. These are available on an exchange basis only - click 'Workshop' on the menu, we might have what you require ready and waiting, but be quick, stock changes all the time. We are happy to share the experience and techniques Jem Engines have acquired in over 30 years of engine-building - you will find a lot of useful information in 'Workshop' too!

Jem Engines has  a large stock of quality
Used Parts (e.g. rocker covers, timing covers, sumps etc) email us to see if we have what you are looking for.


All our gaskets are manufactured specifically for us (all 'soft cut' gaskets are made in-house on our own CNC laser gasket profile cutting machine), and are the result of 20 years experience repairing and remanufacturing these engines. These sets are complete and comprehensive, unlike others sets on the market, we pack everything you need to complete your build, including alternatives where necessary. 

We supply many gaskets individually, such as water pump, thermostat and sump gaskets.

Note: each gasket set or individual gasket pack contains manufacturer's specified torque settings and technical information you might need



Our NEW replacement water pumps are to original specifications by leading OE manufacturers and include fitting gasket..


Water pump failures may be attributed to any of the following:

  • Bearing failure (noisy, caused by over-tightening of fan belt)

  • Mechanical seal failure (leaking)

  • Poor flow rate causing engine overheating (Impeller corrosion due to improper water treatment)

In the majority of cases, the most economic option is to replace the entire pump. However, repair kits are available for a few engine types.

New replacement parts for your own Kubota Water Pump; Gaskets, Bearings and Seals.

For a more economic solution, repair kits are available for a small range of water pumps. The repair kit consists of the bearing, the carbon seal and the gasket. To replace the bearing and seal requires the technician to remove the impeller and press the old components out of the housing. When installing the impeller back on the shaft it is important to set the clearance between the impeller and pump body to the correct value. It is best to measure this clearance before removing the impeller in the first place.


Our NEW replacement thermostats are to original specifications by leading OE manufacturers and include fitting gasket..


Thermostat failures can be diagnosed by any of the following symptoms::

  • Overheating (thermostat sticking in closed position)

  • Overcooling (thermostat sticking in open or partially open position)

  • Erratic overheating and overcooling (thermostat sticking randomly in position)

In the majority of cases the most economic option is to replace the thermostat.


Our reconditioned service exchange fuel pumps are overhauled to original manufacturer's specifications and calibrated on our in-house Hartridge Injection Pump Test Bench.


Fuel pump failures can be diagnosed by any of the following symptoms:

  • Poor starting

  • Excessive Smoke

  • Lack of power

Fuel pump failures can be caused by any of the following:

  • Incorrect grade of fuel

  • Water in the fuel

  • Dirt and other contaminants in the fuel (including deliberate sabotage !)

In the majority of cases the most economic option is to replace the entire pump with a service exchange pump (select the correct pump for your application from the options below).

It is essential when removing the fuel pump from the engine, that the shims between the fuel pump body and the cylinder block are retained for re-use. Do not send the shims to us with the fuel pump for replacement (they are known to stick to the pump and should be removed).

The reconditioned pump is not supplied with shims. The original shims should be reinstalled, the spill timing checked and the shims added or removed as necessary.

Important: When reinstalling the fuel pump, care must be taken to ensure the rack pin is correctly engaged with the governor fork. This can be facilitated by using the stop lever control to align the slot in the governor fork with the rack pin on the fuel pump. Failure to do this will result in damage to the governor fork. 

Your old unit MUST be received by ourselves prior to despatch of your replacement unit.

Your old unit MUST be the correct type for the application and undamaged.

Our unique pump code and serial number system ensures total traceability of each build.


Each injector is fitted with a new nozzle and the pressure set to manufacturer's specification. The spray pattern is also verified that it is correct for the specific nozzle.

Our nozzles are uniquely marked for traceability and quality assurance.

Spill pipes are often damaged when being removed from the engine. These replacement spill pipes are to OE specification and are a direct replacement. They are plated for longevity.


All our bearings are to original specification by leading OE manufacturers.. Available in standard (std) and a range of undersizes where the crankshaft has been reground. If you require your crankshaft reground, Jem Engines can offer this service in-house for the entire Kubota engine range.



Made to original specification by leading OE manufacturers. In any major overhaul of an engine where the standard size of the cylinder bores is worn and beyond reuse specification, it is normal practice to rebore the cylinders which in turn requires the use of over size pistons. In the worst cases, new cylinder liners may be required. Jem Engines offer standard (std) and a range of oversize pistons and rings and also cylinder liners.


We offer comprehensive range of Kubota conrods remanufactured to exacting standards in our own workshop..
Each conrod is checked for bend and twist.  A non destructive crack-test (NDT) is carried out.
Each conrod and cap are lightly ground on the joint faces. The cap is assembled to the conrod and the bolts torqued 
Each conrod bore is precision honed to the makers specification, and roundness is maintained to within 0.0001mm (one tenth of a thou)

The small end bush is inspected and replaced if required.
Supplied on outright basis - no exchange required



Packed as engine sets - every core plug you need for your application - choose between cylinder block set or cylinder head set.

These are also known as Freeze Plugs or Expansion Plugs. All metric sizes 18,  20, 22, 24, 28, 30, 32, 35, 45mm. Plated.

Core plugs may need to be replaced if your engine has been subjected to frost or if insufficient corrosion protection has been added to the coolant and the plugs have rusted.

The plugs should be installed square to the bore using sealing or retaining compound.


All our stop solenoids, glow plugs and alternators are made to original specification by leading OE manufacturers..


​All items are checked as working when they leave our care. As we have no way to determine if an electrical part was used for troubleshooting by the purchaser and damaged during that process, we do NOT allow returns for electrical items. Please be certain of your need for an electrical item before placing an order, and that your installation of it will not damage it