Kubota D1105 Industrial Engine: Specs, Variants, Service & Parts

By the Alpine Equipment service team · Reviewed by Alpine's Kubota-certified industrial engine technicians · American Fork, UT · Updated July 2026

Key Takeaways

• The Kubota D1105 is a 1,123 cc (1.123 L, 68.53 cu in), three-cylinder, water-cooled industrial diesel with a 78.0 × 78.4 mm bore and stroke, rated at 18.5 kW (24.8 hp) at 3,000 rpm naturally aspirated and 24.5 kW (32.9 hp) turbocharged.
• No D1105 variant has any aftertreatment at all. No diesel oxidation catalyst, no particulate filter, no SCR, no DEF tank — and Kubota's workshop manual lists EGR as "None." There is no ash-cleaning interval and no regeneration cycle to force, on any build in the family.
• It still meets EPA Tier 4 and EU Stage V, on combustion design alone, because rated output stays under the 19 kW threshold. The reflexive "Tier 4 means a DPF" rule is simply wrong on this engine.
• The whole family is indirect injection, started by glow plugs. That is why the most-reported D1105 fault — hard cold start with white smoke — is a glow-plug-circuit question before it is a worn-engine question.
• The numbers a technician asks for first: firing order 1-2-3, cold valve clearance 0.145–0.185 mm (0.0057–0.0073 in) checked every 800 hours, compression 3.73–4.11 MPa (541–597 psi) with an allowable limit of 2.26 MPa, injection 13.73 MPa at 18° BTDC.
• Oil capacity is 5.1 L (about 1.35 US gal), not the 4.0 L copied across spec databases — that figure comes from a superseded manual. Kubota does publish a bare-engine coolant volume here, 3.1 L with the standard radiator. Both are bare-engine numbers; verify against your machine's manual by serial number.
• Where to get it serviced: Alpine Equipment is a Kubota Industrial Engine Elite Dealer working in-shop in American Fork and in the field across Utah County and Salt Lake County, with genuine Kubota parts shipped nationwide.

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The Kubota D1105 is a 1,123 cc, three-cylinder, water-cooled, indirect-injection industrial diesel built in rated outputs from 18.5 kW (24.8 hp) naturally aspirated to 24.5 kW (32.9 hp) turbocharged, spanning EPA Tier 2 through EPA Tier 4 and EU Stage V. Almost nobody buys one on purpose. You inherit it — already bolted into a rough-terrain scissor lift, a light tower, a stand-on mini skid or a generator set — and you go looking for it on the cold morning it turns over happily and refuses to light.

The single most useful thing to know before you order a part or book a repair is a negative: this engine has no aftertreatment on any variant, and no direct-injection version of it exists. Both facts change what you should be looking at, and both are missing from nearly every page that ranks for it. Alpine Equipment — the #1 Kubota Industrial Engine service & parts center in the U.S., and a Kubota Industrial Engine Elite Dealer. We service and supply genuine parts for the D1105 whatever badge is on the machine around it, in-shop in American Fork and in the field across Utah County and Salt Lake County. If you already know what you need, request a quote or talk to a Kubota engine specialist.

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What the Kubota D1105 Is

The Kubota D1105 is a vertical, water-cooled, four-cycle, three-cylinder industrial diesel of 1,123 cm³, sold by Kubota Engine America to equipment manufacturers rather than to end users. It is one of Kubota's 05 Series — the same block family as the D1005 below it and the D1305 above it — and Kubota describes it as a leading model in that series precisely because it turns up in so many different machines.

Three terms decide most of what follows, so in plain English. Indirect injection means fuel is sprayed into a small swirl chamber above the piston rather than straight at the piston crown; Kubota's version is the spherical E-TVCS combustion chamber. It runs quieter, tolerates poorer fuel, and — this is the part that matters — it needs glow plugs, heating elements that warm the chamber so the first compression stroke can light the charge. Aftertreatment is anything in the exhaust that cleans the gas on the way out: a catalyst, a particulate filter, or a urea-based SCR system. The D1105 has glow plugs and no aftertreatment, and those two facts drive half this article.

Where you will find it: rough-terrain scissor lifts, vertical-mast light towers, stand-on and mini skid steers, compact excavators, small generator sets and welder-generators, chippers, compaction and turf equipment — almost always wearing another manufacturer's paint.

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Kubota D1105 Specs at a Glance

These are the constants — the figures that hold across the whole D1105 family. What changes between variants is in the next section; what changes between host machines is in the fluids section below.

Spec	Value
Configuration	Vertical, water-cooled, 4-cycle, 3-cylinder diesel
Displacement	1,123 cm³ / 1.123 L (68.53 cu in)
Bore × stroke	78.0 × 78.4 mm (3.07 × 3.09 in)
Combustion chamber	Spherical E-TVCS — indirect injection
Starting	Cell starter with glow plugs (not an air heater)
Firing order	1-2-3
Rotation	Counter-clockwise viewed from the flywheel side
Compression ratio	24 : 1
Valve clearance (cold)	0.145–0.185 mm (0.00571–0.00728 in), intake and exhaust alike
Valve-clearance check interval	Every 800 hours
Compression pressure	3.73–4.11 MPa (541–597 psi); allowable limit 2.26 MPa (327 psi)
Injection pump	Bosch MD type mini pump
Injection (nozzle) pressure	13.73 MPa (140 kgf/cm², 1,991 psi); bench range 13.73–14.70 MPa
Injection timing	18° BTDC
Idle / maximum bare speed	850–950 rpm / 3,200 rpm
Thermostat	Starts to open 69.5–72.5 °C (157–163 °F), fully open 85 °C
Fan-belt tension	7–9 mm (0.28–0.35 in) deflection at mid-span
Electrical	12 V, 1.0–1.2 kW starter; 12 V alternator, 360 W on the E series and 480 W on the E3B; 12 V 65 Ah battery
Dry weight	93 kg (205 lb) naturally aspirated · 97 kg (214 lb) turbocharged
EGR	None

Rated output, torque and emissions certification move with the variant, so they are deliberately not on this table. The figures above come from Kubota's workshop manual for the 05-E3B series and the 05-Series operator's manual. One caution: a compression ratio of 22:1 circulates on third-party spec sites for the legacy D1105-B engine and was not found in a Kubota manual — treat it as third-party, and confirm against the manual for your engine serial number before machining, torquing or ordering.

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Kubota D1105 Variants Decoded

Search results treat "D1105" as one engine. Kubota built it as a family. On this engine the differences are smaller than on Kubota's larger V-series — and the reason they are smaller is itself the story.

Reading the suffix. Kubota's designations are legible once you know the pattern, and Kubota's own model-number guide shows where the string is stamped:

• D = three cylinders in the 05 Series (a leading V means four).
• 1105 = the displacement class, roughly 1.1 litres.
• T = turbocharged.
• E2 / E3 / E4 = the emissions certification generation — Tier 2, interim Tier 4, Tier 4.
• B = a build or specification revision.
• BG / BG2 = the generator-drive build, rated at 1,800 rpm.
• K = electronically controlled fuel injection, which Kubota markets as TVCR.
• A trailing code such as -U25 on D1105-E2-U25 belongs to the equipment manufacturer, not to Kubota.
• There is no combustion-system code anywhere in the family, and that is not an omission. Kubota has never built a direct-injection version of this engine. Every published D1105 uses the spherical E-TVCS chamber and glow plugs.

Variant	Combustion & aspiration	Rated output	Emissions certification	Aftertreatment	DPF?	DEF?
D1105-E (base, 05-E series)	E-TVCS indirect, glow plug, natural	18.7 kW / 25.0 hp @ 3000 (SAE net intermittent); 16.4 kW / 22.0 hp continuous	Pre-Tier 4	None	No	No
D1105-T-E2B	E-TVCS indirect, glow plug, turbo	24.5 kW / 32.9 hp @ 3000; 88.1 N·m (65.0 lb-ft) @ 2000	EPA/CARB Tier 2, EU Stage IIIA	None	No	No
D1105-T-E3B	E-TVCS indirect, glow plug, turbo	24.5 kW / 32.9 hp @ 3000; 88.1 N·m @ 2000	EPA/CARB interim Tier 4, EU Stage IIIA	None	No	No
D1105-E3B	E-TVCS indirect, glow plug, natural	18.5 kW / 24.8 hp @ 3000; 71.5 N·m (52.7 lb-ft) @ 2200	EPA/CARB Tier 4	None	No	No
D1105-E4B (current mainstream)	E-TVCS indirect, glow plug, natural	18.5 kW / 24.8 hp @ 3000; 71.5 N·m @ 2200	EPA/CARB Tier 4, EU Stage V, India BS V	None	No	No
D1105-E4-BG (generator drive)	E-TVCS indirect, natural	Standby 11.5 kW / 15.4 hp @ 1800; continuous 10.1 kW / 13.5 hp @ 1800	EPA/CARB Tier 4, EU Stage V	None	No	No
D1105-K (electronically controlled)	E-TVCS with electronic injection (TVCR), natural	18.5 kW / 24.8 hp @ 3000; 72.4 N·m @ 2200	EPA Tier 4 (North America), EU Stage V, China IV	None	No	No
D1105-E2-BG · -E3-BG · -BG2 · -E4-BG2	E-TVCS indirect, natural	Published as separate Kubota product records; individual output figures are not reproduced here	Tier 2 / Tier 4 / EU Stage V by suffix	None listed	No	No

The one-sentence answer nobody else publishes. No Kubota D1105 variant — naturally aspirated, turbocharged, generator-drive or electronically controlled — carries a diesel oxidation catalyst, a diesel particulate filter, an SCR catalyst or a DEF tank. Kubota's aftertreatment field is blank on every D1105 product record, and the workshop manual lists EGR: None.

Why an engine can be Tier 4 with nothing in the exhaust. Kubota certifies the D1105 to EPA Tier 4 and EU Stage V through combustion design alone — the E-TVCS chamber, and the electronically controlled TVCR system on the -K — because rated output stays under the 19 kW threshold in the EPA's nonroad diesel standards, where the smallest power band is not driven to a filter. The habit runs the other way on bigger engines, and the habit is where the bad advice comes from: on Kubota's 3.8-litre V3800, some variants genuinely do run a particulate filter and a DEF tank. A technician who learned the rules on a V3800 will misread a D1105. If a shop tells you your D1105 needs a forced regeneration, it is describing a component the engine does not have.

And the second structural fact: it is an indirect-injection engine, all the way across the family. No swirl chamber lights a cold charge on its own, which is why every one of these engines has glow plugs and none has an air heater. Hold on to that — it is the whole explanation for the failure pattern further down this page, and it is why a D1105 breaks differently from the direct-injection and common-rail engines above it in Kubota's range.

If you are not certain which one you have, our guide to identifying the Kubota engine in your equipment shows where the model and serial plates live. Match the full string on the nameplate, not just "D1105."

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Which Machines Run a Kubota D1105

Host applications are where bad information travels fastest, because parts sellers publish brand lists nobody sources. Every row below names the document it came from, and anything that could not be traced to a manufacturer's own paperwork is either hedged in place or absent.

Host machine	D1105 designation as printed	Source strength
Genie GS-2669 RT / GS-3369 RT / GS-4069 RT rough-terrain scissor lifts	24.8 hp, 18.5 kW Kubota D1105, Diesel, T4i/T4f, Stage IIIA/V in the power-options table	Strong — and current. Genie's 2024 RT scissor specification PDF lists the D1105 as the only diesel on the sheet; the Kubota WG972 gas option appears on earlier sheets only. This is a current-production pairing, not a legacy one
Ditch Witch SK800 stand-on mini skid steer	Engine: Kubota D1105, EPA Tier 4, EU Stage IIIa, 3 cyl, 68.5 cu in, 24.8 hp @ 3000	Strong — Ditch Witch SK800 operator's manual CMW 053-2976, whose cover reads "SK800 — Kubota D1105," plus parts manual 053-3000
Terex / Genie RL4 and AL4 vertical-mast light towers	Terex OEM part 1268467GT — ENGINE KUBOTA D1105; also catalogued as D1105-E3BG	Strong for the part number, medium for the model-year range — Terex/Genie OEM part listings
Allmand Night-Lite Pro II V-Series light tower	Kubota D1105, 13.5 hp @ 1800 rpm, roughly 8 kW prime	Medium-strong — Allmand product literature
Kubota U25S compact excavator	D1105-E2-U25, replacement engine P/N 1J033-00001	Medium-strong — Kubota USA OEM parts catalog. Confirm in the dealer parts system before ordering
Bobcat 553 skid steer, later builds	D1105-E / D1105-B, 24.8 hp (18.5 kW); Bobcat reman P/N 6678783, Tier 2 P/N 6685655	Medium — reman part listings and build-year databases, not a Bobcat specification sheet. The 1995–2002 553 is a D1005, one displacement class down
JLG 340AJ articulating boom lift	Widely listed as a D1105 at 24.8 hp	Medium — hedged deliberately. JLG's own parts manual confirms a Kubota engine installation but never prints the model designation. The D1105 attribution traces to aggregators and dealer spec sheets. Confirm on the data plate
Light towers, small generator sets, welder-generators, chippers, compaction and turf equipment	D1105 industrial and -BG generator-drive builds	Strong for the category, not for specific models. The -BG build exists precisely for 1,800 rpm constant-speed generator drive

The D1105 also appears in Kubota's own compact tractor line, in the B2601. That is a machine-dealer product and outside what an engine service and parts center covers — it is here only so the engine list is honest.

Why this particular list matters locally. Read the strong-sourced rows again: rough-terrain scissor lifts, light towers, stand-on mini skids and small gensets. Those are rental-fleet machines, and they are the exact machines Alpine already rents and services across Utah County and Salt Lake County. Alpine is also an authorized repair facility for JLG, Xtreme, Snorkel and Genie. So on a Genie RT scissor lift with a D1105 under the deck, the engine and the lift are the same shop — the Kubota engine credential and the aerial-lift credential land on the same machine, which is not a combination a parts reseller or a general diesel bay can assemble. We service those machines and the engines inside them; we are not a Genie or a Ditch Witch dealer, and this article is not claiming otherwise.

Commonly assumed, but not a D1105

These pairings circulate constantly in blog posts, forum threads and aftermarket listings. Each one is wrong, and in each case the correct engine is published:

Claim in circulation	What the manufacturer actually says
Toro Dingo TX 1000 runs a D1105	It runs a Kubota D1305 — 24 gross hp @ 2600 rpm
Takeuchi TB016 runs a D1105	Yanmar 3TNV70, EPA Tier 4, 3 cyl / 52.1 cu in, on Takeuchi's own spec sheet
SkyTrak 6036 / 6042 / 8042 / 10042 / 10054 telehandlers run a Kubota three-cylinder	Cummins throughout — 4BT3.9, 6BT5.9, QSB3.3T / QSB4.5T, QSF3.8. No Kubota three-cylinder appears anywhere in the SkyTrak line
Ditch Witch SK1050 runs a D1105	Yanmar 3TNV88C, 37 hp. The SK800 is the D1105 machine; the SK1050 is not
Vermeer CTX160 mini skid runs a D1105	Kohler
Bobcat 463, and the 1995–2002 Bobcat 553	Kubota D1005, one displacement class down

The engine does turn up across a wider range of manufacturers than the table above — reman-engine and rebuild-kit fitment catalogs list it against a long tail of compact excavators, skid steers and rollers from several brands. Those catalogs establish a category, not a fitment, so no model numbers from them are printed here. A brand list is a category signal, not a fitment.

One more that costs people real money: the D1105 and the D1305 are not interchangeable, even though they nearly look it. They share the 05-Series block family and the same basic footprint, and the D1305 adds roughly 12% displacement on a longer 88 mm stroke. Field swaps happen constantly. The exhaust manifolds are not interchangeable — different port size and bolt pattern — so a swap that looked like a bolt-in becomes a fabrication job at the worst possible moment. Read the data plate before you buy a used engine, not after.

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Kubota D1105 Oil Capacity and Fluids

Fluid	Figure	Notes
Engine oil	5.1 L (about 1.35 US gal) — standard oil pan	Kubota recognises 110 mm, 125 mm and 130 mm pan depths, all on the same 200-hour change interval
Coolant	3.1 L (0.82 US gal / 3.3 US qt) — standard radiator	Kubota does publish this figure for the bare engine, which is unusual — see below
Oil specification	API class CF or better	The older 05-Series manual says CD grade or higher; CF or better is the current recommendation
Oil viscosity	SAE 30, or 10W-30 / 15W-40, above 25 °C · 10W-30 or 15W-40 from −10 to 25 °C · 10W-30 below −10 °C	Utah's winter mornings sit in the bottom band far more often than people fill for
Coolant type	50/50 long-life coolant and clean water	Change every two years
Fuel	Diesel No. 2-D (ASTM D975)

The correction worth owning: it is 5.1 litres, not 4.0. Spec-scraper databases publish 4.0 L for this engine, usually alongside a 101 mm oil pan. That figure comes from an older D1105-B-era manual and it has been copied from site to site ever since. Kubota's current workshop manual and the 05-Series operator's manual both print 5.1 L. If you filled to 4.0 litres because a spec table told you to, the engine has been running a litre light — on a crankcase this small, that is a meaningful fraction of the oil in it.

And the caveat that applies to both numbers. 5.1 L and 3.1 L are bare-engine figures, for the engine as Kubota ships it with a standard pan and a standard radiator. Host manufacturers re-pan and re-radiate constantly — that is exactly how the shallow-pan variant got into circulation in the first place. Treat these as the engine-level reference, then fill to the dipstick against your machine's own manual, matched to its serial number. Publishing one capacity with no context is how crankcases end up overfilled and cooling systems end up short, and it is the single most-copied error in this category.

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Kubota D1105 Service Intervals

This is Kubota's own schedule, from the workshop manual's maintenance check list and cross-checked against the 05-Series operator's manual. The two agree.

Interval	Item
First 50 hours	Change engine oil and replace the oil filter cartridge
Every 50 hours	Check fuel hoses and clamp bands
Every 100 hours	Clean the air-cleaner element (replace after six cleanings) · clean the fuel filter element · check fan-belt tension and condition · check battery electrolyte
Every 200 hours	Change engine oil · replace the oil filter cartridge (all three pan depths) · check radiator hoses and clamp bands · check the intake air line
Every 400 hours	Replace the fuel filter cartridge · remove sediment from the fuel tank
Every 500 hours	Clean the water jacket and radiator interior · replace the fan belt · replace the air-cleaner element
Every 800 hours	Check valve clearance — 0.145–0.185 mm cold
Every 1,500 hours	Check fuel-injection nozzle pressure (dealer) · check the turbocharger (dealer, -T builds)
Every 3,000 hours	Check the injection pump · check the injection timer (dealer)
Every year	Check electrical wiring for damage and loose connections
Every 2 years	Change radiator coolant · replace radiator hoses and clamps · replace fuel hoses and clamps · replace the intake air line · replace the battery

There are no aftertreatment service items on a D1105 — and that is a real ownership-cost advantage nobody writes about. No ash-cleaning interval. No forced-regeneration procedure. No DEF quality check, no DEF filter, no NOx sensor branch. On a comparable Tier 4 engine one power class up, the ash service alone is a scheduled off-machine job with a parts bill attached. Here the schedule above is the whole schedule. If you run a fleet of light towers or scissor lifts, that difference compounds every year.

Kubota does flag several of these items as EPA emission-related critical parts — the oil change, the oil filter, the air cleaner, the fuel hoses, the intake air line, the injection nozzle and the turbocharger. That is a factual reason to route those specific items to a shop with the tooling and genuine parts access. It is not a warranty statement, and no article can make it one.

One extended-interval exception worth knowing about. Kubota Engine America publishes a 1,000-hour oil change interval for the D1005-E4BG and D1105-E4BG running at 1,800 rpm in light-tower applications — conditional on ultra-low-sulfur diesel, API CK-4 oil, defined load and duty-cycle limits, and a documented maintenance record, with approval coming from Kubota Engine America rather than from any shop. If you run light towers, that is worth pursuing formally; if you assume it applies to your unit without the paperwork, you have simply stretched the interval on your own authority. For how these intervals sit alongside the rest of the Kubota industrial line, see the Kubota industrial engine maintenance schedule.

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Common Problems on the Kubota D1105

Start with the cause, because it reorders everything below it. This is an indirect-injection engine, so glow plugs are not a cold-weather convenience — they are how it lights. A swirl-chamber engine relies on a heated chamber to fire the first charge, which is why the single most-reported D1105 complaint, hard starting with white smoke on a cold morning, points at the glow-plug circuit long before it points at worn rings or tired compression. White smoke in that situation is unburned fuel, not oil: the fuel went in and never lit.

That is also why this engine's problem list looks nothing like the list for Kubota's larger V-series engines. On a common-rail V3800, the same crank-and-no-fire symptom sends you to rail supply and electronics. Here it sends you to three plugs, a feed wire and a relay. Same symptom, completely different first move — and a shop that does not know which engine it is looking at will start in the wrong place.

The list below is ordered by what to check first, not by what is most dramatic. Items drawn from service work and owner forums are reported patterns, not manufacturer defect statements, and they are labelled that way.

1. The glow-plug circuit — the signature D1105 fault. Hard starting plus white smoke means plugs, the feed wire to them, or the glow-plug timer or relay. A relay that works intermittently is a well-documented cause and it defeats a lot of DIY diagnosis, because the engine starts fine on the day you test it. Test plugs individually rather than as a set, and test the feed before condemning any of them. Common OEM plug numbers in this family: 16281-65510, 16851-65510, 16851-65512. For the full cold-morning sequence — plugs, battery condition, fuel gelling and what changes below freezing — see why a Kubota diesel won't start in the cold.
2. Air in the fuel system after a filter change. The most-reported "it ran fine yesterday and now it will not start." Bleed the system properly. A trapped-air no-start is not a pump failure, and treating it as one is expensive.
3. Loss of prime while the engine is running. A suction-side leak — a fuel line, a clamp band, or the filter cup seal. Kubota's own 50-hour item is "check fuel hoses and clamp bands," and it is one of the most skipped lines on the whole schedule.
4. The fuel shut-off solenoid and its relay. Corroded pins and a failed relay both imitate a dead engine perfectly. Diagnose the cheap end first.
5. Injection nozzles. Black smoke, rough running, power loss and poor shutdown on higher-hour engines. Kubota's interval is a nozzle-pressure check at 1,500 hours; bench specification is 13.73–14.70 MPa.
6. Injection pump and timing. Timing specification is 18° BTDC. Runaway is reported after pump work — a mis-set rack — and after injector drive-pin failure. This is the clearest argument on the list that the injection pump is not a driveway job.
7. Turbocharger wear on -T builds. Shaft play and oil-seal leakage, almost always downstream of a restricted air cleaner or stretched oil changes rather than a turbo defect. Kubota's check interval is 1,500 hours.
8. Cooling-system neglect on a very small system. Three point one litres leaves no margin at all. Air working into the coolant and scale in the water jacket are both commonly reported; Kubota asks for the water jacket and radiator interior to be cleaned at 500 hours and the coolant changed every two years, and the thermostat should start opening at 69.5–72.5 °C.
9. Compression loss on high-hour units. Specification is 3.73–4.11 MPa (541–597 psi) with an allowable limit of 2.26 MPa (327 psi). Below the limit, or with a large spread between cylinders, it stops being a repair conversation.

Working a symptom rather than a code? The Kubota engine troubleshooting guide walks won't-start, overheating, low-power and smoke from the free checks forward. And one honest note on codes: a mechanical D1105 does not set engine fault codes at all — it has no engine control module to set them. If there is a number on a display in front of you, it belongs to the host machine's own controller, not to the engine. What Kubota engine error codes mean covers the electronically controlled engines where codes genuinely exist, and explains how to tell the two situations apart.

Draper — rental fleet, rough-terrain scissor lift, hard cold start with white smoke

A rental yard in Draper had a D1105-powered rough-terrain scissor lift that started fine off the yard's own warm-up routine and stranded crews on cold mornings, blowing white smoke for thirty seconds before it caught. Three new glow plugs had already gone in and changed nothing. The plugs were never the fault — the glow-plug timer relay was closing intermittently, so the plugs energised on some cycles and not others, which is exactly the pattern that makes a fault look like it "comes and goes with the weather." The transferable rule: on an indirect-injection engine, prove the plugs are actually being fed before you replace them. Parts that test fine on the bench tell you nothing about what reaches them at 6 a.m.

Orem — contractor, stand-on mini skid, no-start the morning after a filter change

A site contractor in Orem had a stand-on mini skid that had run all week, taken a routine fuel filter cartridge on Friday afternoon, and refused to start on Monday. The advice already offered was that the injection pump had failed over the weekend. Pumps do not fail while parked. Changing a fuel filter opens the fuel system, and if it is not bled properly the trapped air stops fuel reaching the cylinders — the same no-start, at roughly one percent of the cost. Bleed first. Every time the symptom starts immediately after someone opened the fuel system, the fuel system being open is the first suspect, not a coincidence.

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Parts: What Wears Out and What to Stock

In rough order of how often they come across the bench:

1. Glow plugs and the glow-plug relay or timer. Top of this list on this engine specifically, for the reason the previous section spent 400 words on.
2. Fuel filter cartridge and the filter cup seal. The seal is the part people forget, and it is what turns a routine filter change into a slow loss of prime.
3. Fuel hoses and clamp bands — Kubota's 50-hour check item and a two-year replacement item.
4. Oil filter cartridge — every 200 hours, on all three pan depths.
5. Air-cleaner element — cleaned at 100 hours, replaced after six cleanings or annually.
6. Injection nozzles.
7. Fuel shut-off solenoid.
8. Fan belt, thermostat and water pump.
9. Radiator hoses and clamps.
10. Turbocharger cartridge and the oil feed and return lines — -T builds only.
11. Head gasket and seals.
12. In-frame overhaul kits — pistons, rings, bearings, liners.

If you run a rental fleet, stock the top five and nothing below them. A glow-plug set, a relay, filters and a fuel-hose kit per machine turn a cold morning into a delay instead of a lost day. Anything from the injection pump downward is a shop item anyway, so carrying it mostly ties up capital.

Order the genuine Kubota part against your engine serial number, not the machine model. The same host machine carries different D1105 builds across model years, and a light tower and a scissor lift with the same engine family can still take different service parts. Alpine stocks and ships genuine Kubota parts nationwide: see Kubota industrial engine parts online, browse the Kubota parts collection, or request a quote or talk to a Kubota engine specialist with your model and serial.

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When It's a Rebuild Instead of a Repair

Trade consensus puts a well-maintained D1105 beyond 10,000 hours before a major overhaul. That is reported as consensus, not as a Kubota specification and not as a promise about any particular engine — fuel quality, load factor, and whether the 200-hour oil changes actually happened move it by thousands of hours in both directions.

Hours alone should not decide it. The compression gauge should:

Measurement	Figure
Compression pressure, healthy	3.73–4.11 MPa (541–597 psi)
Allowable limit	2.26 MPa (327 psi)
Between cylinders	A large spread matters as much as a low absolute reading

An engine below the allowable limit, or with cylinders that disagree badly with each other, is telling you something an hour meter cannot. Gather that number before making the decision:

Situation	Repair	Rebuild	Replace
Symptom pattern	One system — a relay, a nozzle, a solenoid, a water pump	Low compression across cylinders, oil consumption, blow-by at the fill cap	Block, crank or catastrophic internal damage
Compression	Even and within specification	At or below 2.26 MPa, or badly uneven	Failed cylinder with block damage
Rest of the machine	Sound, worth the investment	Sound, several years of work left in it	Machine itself near the end of its life
What decides it	Diagnose first — most single faults are repairs	A compression and blow-by test, not a guess	Cost of a rebuild approaching a replacement engine

The test comes before the decision. A compression test and a blow-by check cost a fraction of a rebuild and routinely find that a smoking, hard-starting engine has a glow-plug circuit fault and one tired nozzle rather than three worn cylinders. For what a proper rebuild involves and the capability it requires, see inside a Kubota industrial engine rebuild.

For market context only: third-party parts sellers put overhaul kits for this engine class at roughly $230–$350, a do-it-yourself rebuild all-in at $2,800–$4,500 once machine-shop work is included, and 40 to 60 hours of labour, against $14,000 or more for a new engine. Those are published ranges from parts sellers, not an Alpine quote — what a specific rebuild costs is only knowable after a teardown.

Springville — owner-operator, high-hour light tower

An owner-operator near Springville brought in a D1105-powered light tower with oil consumption climbing, visible blow-by at the fill cap and a stack that stayed hazy at full load. That combination describes several systems tired at once rather than one part failed, and the compression numbers agreed: two cylinders under the 2.26 MPa allowable limit, with a wide spread across the three. What decided the outcome was not the engine, though — it was the tower. The mast, the winch and the generator end were sound, with years of rentable life left in them, which is exactly the situation where a rebuilt engine returns the money. Had the rest of the machine been near the end of its own life, the same compression numbers would have pointed the other way.

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Getting a Kubota D1105 Serviced

The D1105 sits in an awkward gap in the service market. A Kubota tractor dealer generally will not take your scissor lift. The aerial-lift dealer is not tooled or stocked for the engine inside it. A general diesel shop can change filters and hoses, but often cannot say on the phone whether the engine in front of it has any aftertreatment at all — which is precisely the question that decides half the diagnosis. So a small three-cylinder with a simple fault gets bounced between shops before it reaches one that starts by reading the nameplate.

Alpine Equipment is an engine service and parts center, and we service the engine whatever it is bolted into. As the #1 Kubota Industrial Engine service & parts center in the U.S. — a Kubota Industrial Engine Elite Dealer and the sole US recipient of Kubota's 2025 Customer Experience Excellence Award — we run factory Kubota diagnostic tooling, stock genuine parts, and work in-shop in American Fork and in the field across Utah County and Salt Lake County. On the machines this engine actually lives in, that pairs with something unusual: Alpine is also an authorized repair facility for JLG, Xtreme, Snorkel and Genie, so a rough-terrain scissor lift with an engine fault and a lift fault does not need two vendors and two trips.

What that does not include. Alpine works on the engine, not the machine wrapped around it. Booms, masts, hydraulics, undercarriage, generator ends and the host machine's own controller belong with the machine dealer — and so does anything being claimed under a machine or engine warranty, because a service and parts center is not a warranty administrator. That boundary cuts both ways in the customer's favour: a competent general diesel shop can do routine filters, fluids and belts on a D1105 perfectly well, usually closer to home and often for less. The narrow case where an industrial engine dealer earns the trip is the one this article is about — a fault that keeps coming back, a part that has to be right the first time, or a diagnosis nobody else will put their name to.

Rates: shop service is $145 per hour. Field service is $165 per hour with a two-hour minimum. On an engine this size, a diagnosis at that rate is routinely cheaper than one wrong guess at a nozzle set — and on the most common fault in this article, cheaper than the parts already sitting in the truck.

Have these ready when you call in a D1105:

• The full engine model string off the nameplate — D1105-E4B or D1105-T-E3B, not "D1105"
• The engine serial number — this is what parts are ordered against
• The host machine make, model and hour meter
• The exact symptom, and when it happens: cold start only, under load, after a filter change, at idle
• Whether anyone has already replaced parts on a guess, and which ones

Questions worth asking any shop — use them on us, on the machine dealer, and on the diesel bay down the street. None of them asks a shop to be Alpine. They ask it to say plainly what it can and cannot do on this engine, which is all you need to route the job correctly.

1. Which D1105 build do you think this is, and what on the machine tells you that?
2. Do you have the Kubota workshop manual for this series, or a generic spec table?
3. Will you test the glow-plug circuit — feed, relay and plugs individually — before quoting parts?
4. Will you confirm the fault and quote before replacing anything non-diagnostic?
5. Can you source genuine Kubota parts against the engine serial number rather than the machine model?
6. What is your labour rate, and is there a minimum on a field call?

How to read the answers. A shop that says it works from a spec table rather than the manual is not a bad shop — it is a shop that should be doing your filters, hoses and belts rather than your intermittent no-start. The answers that should end the conversation are a vague one to question 6 or a no to question 4. For how Kubota's dealer tiers work and what separates them, see who the best Kubota industrial engine dealer is and how to tell.

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Frequently Asked Questions About the Kubota D1105

What is a Kubota D1105 engine?
The Kubota D1105 is a 1,123 cc, three-cylinder, vertical water-cooled, four-cycle industrial diesel sold by Kubota to equipment manufacturers rather than to end users. It uses Kubota's spherical E-TVCS indirect-injection combustion chamber and starts on glow plugs, and it is rated at 18.5 kW (24.8 hp) naturally aspirated or 24.5 kW (32.9 hp) turbocharged. You will usually meet it as the engine inside another manufacturer's machine — a scissor lift, a light tower, a mini skid steer or a generator set.

What are the specs of a Kubota D1105?
The D1105 displaces 1,123 cm³ (68.53 cu in) with a 78.0 × 78.4 mm bore and stroke, three cylinders, a 24:1 compression ratio, a firing order of 1-2-3 and counter-clockwise rotation viewed from the flywheel side. Cold valve clearance is 0.145–0.185 mm on both intake and exhaust, injection pressure is 13.73 MPa at 18° BTDC, and dry weight is 93 kg naturally aspirated or 97 kg turbocharged.

How much horsepower does a Kubota D1105 have?
It depends on the build: 24.8 hp (18.5 kW) at 3,000 rpm on the naturally aspirated D1105-E3B and D1105-E4B, 25.0 hp (18.7 kW) intermittent on the older D1105-E, and 32.9 hp (24.5 kW) at 3,000 rpm on the turbocharged D1105-T-E2B and D1105-T-E3B. The generator-drive D1105-E4-BG is rated much lower because it runs at 1,800 rpm — 15.4 hp standby and 13.5 hp continuous.

What equipment uses a Kubota D1105 engine?
Sourced applications include Genie GS-2669 RT, GS-3369 RT and GS-4069 RT rough-terrain scissor lifts, the Ditch Witch SK800 stand-on mini skid steer, and Terex/Genie RL4 and AL4 vertical-mast light towers, all confirmed in manufacturer documents. The Allmand Night-Lite Pro II V-Series, the Kubota U25S compact excavator and later-build Bobcat 553 skid steers are documented at medium strength, and as a category the engine is common in light towers, small generator sets, welder-generators, compaction and turf equipment. Toro's Dingo TX 1000 and the Takeuchi TB016 are frequently listed as D1105 machines and are not — they run a Kubota D1305 and a Yanmar 3TNV70 respectively.

How much oil does a Kubota D1105 take?
Kubota's current workshop manual and operator's manual both give 5.1 litres (about 1.35 US gallons) with the standard oil pan. The 4.0-litre figure published across spec databases comes from a superseded D1105-B-era manual with a shallower pan and should not be used. Kubota recognises 110 mm, 125 mm and 130 mm pan depths, all on the same 200-hour change interval — and because host machines re-pan the engine, fill to the dipstick against your machine's manual by serial number.

What oil does a Kubota D1105 require?
API service classification CF or better, with viscosity chosen by ambient temperature: SAE 30 or 10W-30/15W-40 above 25 °C, 10W-30 or 15W-40 from −10 to 25 °C, and 10W-30 below −10 °C. The older 05-Series operator's manual specifies CD grade or higher, so an engine of that vintage running CF is correctly served. Kubota Engine America's extended 1,000-hour interval for -E4BG light-tower units specifically requires API CK-4 oil and ultra-low-sulfur fuel.

What does the "E3B," "E4B," "T" and "BG" mean on a Kubota D1105?
E2, E3 and E4 mark the emissions certification generation — Tier 2, interim Tier 4 and Tier 4 — and a trailing B is a build or specification revision. T means turbocharged. BG means the generator-drive build, rated at 1,800 rpm for constant-speed generator and light-tower use, and BG2 is a later revision of it. A K suffix means electronically controlled fuel injection, and a trailing code such as -U25 belongs to the equipment manufacturer rather than to Kubota.

Does a Kubota D1105 have a DPF or need DEF?
No. No D1105 variant has a diesel particulate filter, a diesel oxidation catalyst, an SCR system or a DEF tank, and Kubota's workshop manual lists EGR as "None." Kubota meets EPA Tier 4 and EU Stage V on this engine through combustion design alone, because rated output stays under the 19 kW threshold where the smallest engines are not driven to aftertreatment. There is no regeneration cycle to force and no ash-cleaning interval on any build in the family.

What is the valve clearance and firing order on a Kubota D1105?
Cold valve clearance is 0.145–0.185 mm (0.00571–0.00728 in) on both intake and exhaust, and the firing order is 1-2-3. Rotation is counter-clockwise viewed from the flywheel side. Kubota's schedule calls for the valve clearance to be checked every 800 hours; confirm against the workshop manual for your engine serial number before adjusting.

Why won't my Kubota D1105 start?
On this engine the most common cause of a hard or failed start is the glow-plug circuit — the plugs themselves, the feed wire to them, or an intermittent glow-plug timer or relay — because an indirect-injection engine needs a heated chamber to light a cold charge. The second most common cause is air in the fuel system, which almost always follows a recent fuel filter change that was not bled properly. A failed fuel shut-off solenoid or its relay imitates a dead engine convincingly and is the third thing to check, all before anything with an injection pump attached to it.

What causes white smoke on a Kubota D1105?
White smoke on start-up is unburned fuel, which on an indirect-injection engine points first at the glow-plug circuit — the charge is going in and not lighting. If it persists once the engine is warm, the causes shift to injection timing, worn or leaking nozzles, and low compression. Sweet-smelling white smoke is different again and suggests coolant entering a cylinder. Cold-morning white smoke that clears as the engine warms is the classic glow-plug pattern and is worth ruling out before anything expensive.

What's the difference between a Kubota D1105 and a D1305?
They are the same 05-Series block family with the same basic footprint, and the D1305 adds roughly 12% more displacement through a longer stroke — 88 mm against the D1105's 78.4 mm. That makes them look interchangeable and they are not fully: the exhaust manifolds have different port sizes and bolt patterns and will not swap. Field substitutions do happen, but verify against the data plate and the parts catalog before buying a used engine on the assumption it will bolt straight in.

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Servicing a Kubota D1105 in Utah

Start with the nameplate, then start cheap. The full model string tells you whether you have a naturally aspirated engine or a turbocharged one, a 3,000 rpm industrial build or an 1,800 rpm generator build — and it confirms the thing that reorders every diagnosis on this engine, which is that whatever the string says, there is no filter, no catalyst and no DEF anywhere in the exhaust. Then work the cheap end first: on an indirect-injection three-cylinder, the glow-plug circuit and the fuel system account for most of the calls, and the parts people buy on a guess are usually the ones the test would have cleared.

Past that point it becomes a question of who holds the workshop manual for your series and the genuine parts to finish the job. Bring the engine model string, serial number, hour meter and symptom, and request a quote or talk to a Kubota engine specialist.

Alpine Equipment — Kubota Industrial Engine Elite Dealer
349 S 100 W, American Fork, UT 84003
Serving Utah County & Salt Lake County · Kubota OEM parts shipped nationwide