Kubota D1105 Engine Guide: Fitment, Specs & Repower

The Kubota D1105 is a 1.1 liter (1,123 cc), three-cylinder, water-cooled indirect injection diesel from Kubota’s 05 Series. Kubota calls it a leading model in that series, and it turns up in Kubota’s own RTV utility vehicles, ZD zero-turn mowers and compact equipment, in Toro, Jacobsen and Grasshopper turf machines, in Genie and JLG lifts, in Carrier truck reefers and in generator sets.

That spread is also the problem. “It is a D1105” is not enough information to order a part, because Kubota builds this engine in many application-specific versions, and look-alike machines often run a different 05 Series engine entirely. This guide covers which machines use it, how to identify the exact build, the specs that matter, and how to decide between rebuilding and replacing.

Which Machines Use the Kubota D1105?

The applications below come from the equipment makers’ own service manuals, parts catalogs and spec sheets, not aftermarket listings. Build codes in brackets are the ones those documents list. Makers change engines between serial ranges, so treat this list as the starting point and the engine itself as the final word.

Kubota utility vehicles, mowers, tractors and excavators

• RTV1100 and RTV1140CPX utility vehicles. Kubota’s parts catalog lists more than one replacement engine for each, a D1105-E3-UV build and a later D1105-E4-UV build, so the full model code and serial number on the machine decide which one you need
• RTV-X1100C (D1105-E4-UV-1) and RTV-X1120D (D1105-E4-UV-2): the same engine family in two different builds
• ZD1211 zero-turn (a D1105-E4-ZD build), the newer ZD326H, and the earlier ZD28
• B26 tractor loader backhoe and B2401 compact tractor (D1105-E4-D35)
• U25S compact excavator (D1105-E2-U25)

Turf equipment

• Toro Groundsmaster 7200 (D1105-E2B, naturally aspirated) and Groundsmaster 7210 (turbocharged D1105T-E2B). Toro also built a 7210 with a Yanmar 3TNV88C, which has its own service manual, so look at the engine before you order
• Toro Reelmaster 3100-D (model 03201), where Toro’s parts catalog lists a Toro-specific D1105 build
• Jacobsen SLF 1880 (D1105-E4B-TXRN-1), Jacobsen LF510 and Turfcat (D1105-E4B-TXN-3), and Cushman Truckster, Haulster and Spraytek vehicles (D1105-E4B-TXRN-2), per Jacobsen’s engine parts manual
• Grasshopper 928D front mount mower

Lifts, refrigeration and generators

• Genie GS-2669 RT, GS-3369 RT and GS-4069 RT rough terrain scissor lifts. Genie’s service manual for these models covers a Kubota D1105-E3B and a Perkins 403D-11 on the diesel side, plus Kubota WG972 and GM gas engines, so check which one your lift has
• JLG 340AJ boom lift, diesel units (JLG lists the D1105-E3; gas units use a GM 0.97L)
• Carrier Transicold Supra 950Mt truck refrigeration unit, where Carrier calls the engine a CT3-69TV
• Generator sets built on the D1105-E4-BG (1,800 rpm, 60 Hz) or D1105-E4-BG2 (1,500 rpm, 50 Hz) generator builds

Why “It Is a D1105” Will Not Order You a Part

This is the single most useful thing to understand about this engine. Kubota does not build one D1105. It builds versions that differ in rating, governed speed, emissions generation and even size and weight (the D1105-E4-BG generator build is listed about 1.4 inches longer and 38 lb heavier than the D1105-E4B industrial engine), and it gives them different part numbers.

The RTV range shows it best. Kubota’s own parts catalog lists two different replacement engines for the RTV1100 alone (a D1105-E3-UV and a D1105-E4-UV-A), and separate builds again for the RTV-X1100C and RTV-X1120D. Two machines that look the same in a yard can take different engines.

The emissions generation matters for parts too. Kubota’s workshop manual tells technicians to use only the replacement parts listed for that specific E3B engine, and warns that parts from another emission level, such as E2B, can put the engine out of compliance.

Start with the stamp on the crankcase. It carries the base model and the serial number, and on 05 Series engines the first characters of the serial code the year and month of manufacture. What the stamp does not show is the emissions generation: Kubota says E3B is not marked on the engine and points you to the EPA label on the head cover, where E3B models end in “ET”. Toro’s service manual gives the rest of that code: ES means E2B, ET means E3B and EF means E4B. Our guide to finding your Kubota model and serial number shows where the stamp sits on 05 Series engines.

Kubota D1105 Specifications

Every D1105 shares the same bore, stroke and displacement. What changes from build to build is the rating, the governed speed, the emissions generation, and the size and weight. Figures below are Kubota’s own.

Core specs:

• Type: vertical, water-cooled, four-cycle, three-cylinder indirect injection diesel with Kubota’s E-TVCS combustion chamber
• Displacement: 1,123 cc (68.53 cubic inches)
• Bore and stroke: 78.0 x 78.4 mm (3.07 x 3.09 in)
• Torque: 52.7 lb-ft at 2,200 rpm on the D1105-E4B
• Fuel system on the mechanical engines: Bosch MD-type mini inline injection pump and Kubota mini nozzles (DNOPD type), with a glow plug in each combustion chamber

Machine makers often quote a different number than Kubota’s engine rating because they rate at a different speed or method. Toro, for example, rates the Reelmaster 3100-D at 21.5 HP at 2,500 rpm.

What Goes Wrong on a Kubota D1105?

The mechanical D1105 is a simple IDI engine, and a lot of what gets blamed on a worn-out engine turns out to be fuel or starting trouble. As a Bosch Authorized Service shop, the fuel side is what we test on our benches:

• Hard starting and white smoke on a cold engine. Each cylinder has a glow plug in the combustion chamber, and this engine needs a proper preheat cycle. Weak glow plugs make an otherwise healthy engine feel worn out.
• Air in the fuel system after a filter change or running dry. Kubota’s procedure bleeds at the fuel filter vent plug first, then at the air vent cock on top of the injection pump, and warns that leaving that vent cock open can stop the engine. Our Kubota fuel system bleeding guide walks through the sequence.
• Injector wear showing up as smoke, rough running or poor fuel economy. Kubota’s spec for these nozzles is an opening pressure of 1,991 to 2,133 psi, with no fuel leaking from the seat at 1,849 psi. A pop test checks both, plus chatter and spray pattern. Our mechanical injector testing and rebuild service handles Kubota nozzles.
• Injection pump wear. A tired Bosch MD mini pump can show up as hard starting and a general loss of power that owners put down to the engine being tired.

Those last two are easy to misread as a worn-out engine. A compression test, typically $300 to $500 at a shop, settles the question before anyone spends money on a long block.

Should You Rebuild or Replace a Kubota D1105?

Hours on the meter are a poor guide on equipment that may have sat, idled or run in dust. Compression is the better measure, and Kubota publishes the numbers for these 05 Series engines: 412 to 469 psi is factory spec, and 327 psi is the allowable limit. AERA’s technical bulletin on Kubota compression testing adds that cylinders should be within 10 percent of each other, tested with the nozzles out, the fuel stop pulled and the engine cranking at 250 rpm or more. A cold engine reads 3 to 10 percent low, and an engine close to the limit may run but can be down as much as 25 percent on power.

Broadly:

• Fuel system only. Testing and rebuilding injectors and the injection pump costs a fraction of an engine, and it resolves a lot of “the engine is tired” complaints. We also accept mail-in pumps and injectors from anywhere in the country.
• Mechanical wear with a sound block. Worth rebuilding. Order overhaul parts for your engine’s emissions generation, as Kubota’s manual requires.
• Cracked head, scored block, or a machine where downtime is the real cost. A new complete engine is often the better economics, especially since Kubota kept the mounting points from Tier 2 to Tier 4. We supply new D1105 engines as an authorized Kubota dealer: see our Kubota D1105 engine listing, and if your build is not shown, our Kubota engine sourcing page covers essentially any current Kubota diesel.

Frequently Asked Questions

What engine is in a Kubota RTV1100?

A Kubota D1105, but not always the same build. Kubota’s parts catalog lists two replacement engines for the RTV1100 (a D1105-E3-UV and a D1105-E4-UV-A), and the RTV-X1100C and RTV-X1120D take their own E4-UV builds. Order by the engine stamp and the machine serial number, not the RTV model name.

How much horsepower does a Kubota D1105 have?

Kubota rates the naturally aspirated D1105-E4B at 24.8 HP (SAE gross intermittent) at 3,000 rpm, with 52.7 lb-ft of torque at 2,200 rpm. The turbocharged D1105-T builds are rated 32.9 HP at 3,000 rpm, and the D1105-E4-BG generator build 15.4 HP standby and 13.5 HP continuous at 1,800 rpm. Machine makers often quote a different figure at their own governed speed or rating method.

What is the difference between a Kubota D902 and a D1105?

They are different engine series. The D902 is a Super Mini engine (898 cc, 72.0 x 73.6 mm) and the D1105 is an 05 Series engine (1,123 cc, 78.0 x 78.4 mm). Kubota rates both current versions at 24.8 HP gross, but the D1105 makes it at 3,000 rpm instead of 3,600 and puts out 52.7 lb-ft of torque against 41.4. The D1105 is also longer, taller and about 46 lb heavier, so it is not a bolt-in for a D902. Our Kubota D722 vs D902 vs V1505 guide covers the D902 side, including RTV900 fitment and swaps.

Is the Kubota D1105 the same engine as a D1005 or a D1305?

No. All three are three-cylinder 05 Series engines and they look very similar installed, but the D1005 is 1,001 cc (76.0 x 73.6 mm), the D1105 is 1,123 cc (78.0 x 78.4 mm) and the D1305 is 1,261 cc (78.0 x 88.0 mm). Look-alike machines switch between them, which is a common source of wrong orders: the original ZD326 is a D1005, the ZD326H is a D1105 and the ZD331 is a D1305.

Does the Kubota D1105 have a DPF?

No. Kubota lists no aftertreatment for the D1105 builds on its engine site, including the naturally aspirated D1105-E4B, which meets EPA/CARB Tier 4 and EU Stage V as built. Configurations vary by generation and machine spec, so confirm yours from the emission label on the head cover and the engine stamp.

Can you rebuild a D1105 or is replacement better?

It depends on the condition of the block and head rather than hours on the meter. Kubota’s factory compression spec is 412 to 469 psi with an allowable limit of 327 psi, and cylinders should be within 10 percent of each other. Where the problem is confined to the injectors or the injection pump, servicing the fuel system costs a fraction of an engine.

Getting the Right D1105 the First Time

If you take one thing from this guide, make it the serial number. The D1105 is a proven engine, and the ordering mistakes we see are almost never about the engine itself. They come from someone ordering a part for “a D1105” when Kubota built many different ones for different machines.

Valley Fuel Injection & Turbo is an authorized Kubota engine dealer and a Bosch Authorized Service diesel fuel injection shop in Woodland, California, in business since 1993. We supply new D1105 engines and genuine Kubota parts, and we test and rebuild injection pumps and injectors on our own benches. Call (530) 668-0818 with your machine model and engine serial number, schedule a diagnostic, or ship your pump and injectors through our mail-in rebuild service. You can also read about our Bosch injection pump and injector services. We are at 1243 E Beamer St, Suite C, Woodland, CA 95776, serving Sacramento and Northern California, and shipping nationwide.