Komatsuengine(no series)

Komatsu 2D68E-3A(S/N 00101-UP)

Maintenance schedule, common problems & OEM parts breakdown

The 2D68E-3A(S/N 00101-UP) is a standalone Komatsu industrial diesel engine, not a full machine: a 2-cylinder, water-cooled, naturally aspirated, indirect-injection (swirl-chamber) block displacing about 0.523 L (31.9 cu in), rated 6.3-7.0 kW (8.5-9.4 HP) at 2200 rpm with a mechanical governor and no electronic controls. It is Komatsu's badge-engineered version of the Yanmar 2TNE68 platform, built within Komatsu's broader 2D68E-4D88E small industrial engine range under the -3A mobile-equipment suffix. It powered Komatsu's smallest micro and mini excavators (power shovels) from the late 1990s into the 2010s, including the PC03-2F, PC09-1, and PC10UU-era units, machines running roughly 880 kg (1,940 lb) up to about 1.08 t (2,380 lb) operating weight depending on configuration. A separate N3-prefix family (including 2D68E-N3CB) covers stationary and generator-set duty on the same base block and sits outside this catalog.

Across the 3A/3B/3C mobile-equipment suffixes the core block, bore and stroke, and displacement carry over unchanged; the differences visible in this parts catalog track running production and serial breaks - the alternator, starting motor, and governor linkage each show a parts split at serial 10056 - rather than a ground-up redesign. Because Komatsu built this engine on the same base casting Yanmar sold as the 2TNE68, and other manufacturers' micro excavators of the same era used that block under their own badging, parts and rebuild kits draw from a wider pool than Komatsu's own catalog alone. These host machines sold in low volume and skew toward Japan-domestic-market equipment, so genuine Komatsu parts availability is thin today; owners and shops lean on that shared engine platform's aftermarket support, and confirming the exact serial before ordering matters more than usual given how many closely related suffix codes exist in this family.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.

Komatsu 2D68E-3A(S/N 00101-UP) specifications

Engine

Engine model2D68E-3A — 2-cylinder, vertical inline, water-cooled diesel. Part of Komatsu's 2D68E through 4D88E small industrial diesel engine series.
Gross powerApprox. 6.8-7.0 kW (9-9.4 HP) at 2200 rpm rated speed. Figures vary slightly by reference.
Net power (as installed)6.3 kW (8.5 HP) at 2200 rpm
Displacement0.523 L (523 cc / 31.9 cu in)
Cylinders2, vertical inline
Bore x stroke68 mm x 72 mm, per the shop manual for this engine family. Not independently confirmed for this exact serial range.
AspirationNaturally aspirated
Compression ratio23:1, per the shop manual for this engine family
Emissions certificationCertified as an EPA nonroad industrial diesel engine. No specific Tier rating documented for this exact model in available references — confirm current certification status with your Komatsu dealer.

Weights

Engine dry weightNot published for this exact serial range. Base 2-cylinder engine architecture in this series runs approximately 65 kg (143 lb) dry — confirm the exact figure for this unit with your Komatsu dealer or shop manual.

Dimensions

Overall engine envelopeNot published for this exact model. Base 2-cylinder engine architecture in this series measures approximately 500 mm long x 385 mm wide x 415 mm high (19.7 x 15.2 x 16.4 in) — confirm the exact figure for this unit with your Komatsu dealer or shop manual.
Chassis-type dimensionsNot applicable — this is a standalone engine model with no wheelbase, track gauge, or ground-clearance figures of its own.

Performance

Rated engine speed2200 rpm full-load rated speed, corresponding to the 6.3 kW (8.5 HP) net output
Machine-level performanceTravel speed, drawbar, lift, and gradeability figures do not apply to this standalone engine listing. Those depend on the specific machine this engine powers — check that machine's own spec sheet.
TorqueNot published for this exact engine model in available references.

Service capacities (summary)

Engine oilApprox. 2.5 L (2.6 qt), per the shop manual for this engine family. Not independently confirmed for this exact serial range.
Cooling systemApprox. 3.5 L (3.7 qt), per the shop manual for this engine family.
Fuel tankNot applicable — fuel tank capacity belongs to the host machine, not this engine assembly.
Hydraulic systemNot applicable to this engine assembly.

Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.

2D68E-3A(S/N 00101-UP) fluids & capacities

SystemCapacityRecommended fluid
Engine crankcase (with oil filter)Approx. 2.5 L (0.66 US gal) with filter change, on the mobile/excavator-power build of this engine. Some generator-set builds of the same base block use a shallower pan near 1.5 L (0.4 US gal) — capacity varies by pan configuration; confirm against the dipstick marks for this unit.SAE 10W-30 for warm ambient conditions, SAE 5W-20 for cold conditions, meeting API service classification CC or higher (a higher API letter is acceptable and preferred where available). No proprietary Komatsu oil line is called out in this engine's own documentation for this series; a quality diesel engine oil meeting the stated API rating is acceptable.
Cooling systemApprox. 3.5 L (0.92 US gal) for the engine block and integral water jacket. Total system volume (with radiator, hoses, and host machine routing) runs higher and depends on the host machine build — verify per host.Soft, clean water mixed with a quality antifreeze / anti-corrosion coolant additive. No branded coolant is named in the engine's own documentation; use a phosphate-free, silicate-free formulation that is safe for aluminum components, and drain/refill on the manual's stated interval.
Fuel systemNot applicable at the engine level — fuel tank size is set by the host machine, not the bare engine.Diesel fuel oil equivalent to or better than ISO 8217 DMA, or BS 2869 Part 1 Class A1 / Part 2 Class A2, minimum cetane number 45. Use clean, water-free diesel; avoid low-cetane or contaminated fuel.

Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.

Komatsu 2D68E-3A(S/N 00101-UP) maintenance schedule

Service intervalTasks
Every 50 h
  • Check engine oil level on the dipstick before starting each shift; top up as needed
  • Check coolant level in the sub-tank or radiator; top up with the correct water/antifreeze mix
  • Drain water and sediment from the fuel water separator bowl
  • Inspect the block, injection pump, and hose fittings for fuel, oil, and coolant leaks
  • Check fan and alternator belt tension and condition
  • Clean the air cleaner element and check the intake hose for cracks or looseness
Every 250 h
  • Change engine oil and replace the oil filter cartridge
  • Replace the fuel filter element and clean the water separator screen
  • Check battery electrolyte level and terminal connections
  • Check glow plug preheat operation and wiring connections
  • Re-check and adjust fan/alternator belt tension; replace if glazed or cracked
Every 500 h
  • Check and adjust valve clearance at the rocker arms
  • Check fuel injection timing against factory spec
  • Inspect injector nozzles for spray pattern and opening pressure; recondition as needed
  • Drain and refill the cooling system with a fresh coolant mix
  • Check the governor linkage and adjusting screw for wear or free play
  • Inspect the muffler and exhaust manifold mounting for leaks or cracks
Every 1,000 h
  • Check the water pump for shaft play, seal leakage, and bearing wear
  • Check crankshaft and camshaft drive gear backlash
  • Check cylinder head bolt torque
  • Check starting motor and alternator brushes and wiring for wear
  • Check oil pump output pressure and relief valve operation
  • Check flywheel housing and mounting hardware for looseness
Every 2,000 h
  • Check cylinder compression on both cylinders
  • Inspect or recondition the fuel injection pump
  • Check valve seats, guides, and tappets for wear
  • Check main and connecting rod bearing clearances
  • Flush and pressure-test the entire cooling system
  • Check camshaft and bushing wear
Every 4,000 h
  • Plan a full teardown; inspect cylinder bore, pistons, and rings against factory wear limits
  • Replace main and connecting rod bearings as a set
  • Recondition or replace the fuel injection pump and injector nozzles
  • Resurface or replace the cylinder head if warped beyond spec
  • Replace engine mounts, hoses, and the drive belt as part of the rebuild
  • Recalibrate the governor and injection timing after reassembly

Servicing the 2D68E-3A(S/N 00101-UP) beyond the schedule

Predictive Maintenance & Fluid Analysis

This engine has no ECM and no stored fault codes, so predictive upkeep means physical checks. Read the dipstick for grit and color: metallic glitter flags bearing wear, a milky sheen means coolant is reaching the oil, and a strong fuel smell points to injector leak-by. Watch smoke color at startup and under load - white flags unburned fuel or coolant intrusion, blue flags oil burning past worn rings. Check the water separator bowl at every fuel stop; buildup there predicts injection pump wear before it shows up as rough running.

Corrective & Common Repairs

Hard cold starts usually trace to weak glow plugs or a failing preheat relay, not the injection pump - check preheat draw and glow plug resistance first. If the engine only fires on starting fluid and dies, suspect the injection pump stop solenoid not energizing, or trapped air in the fuel lines after a filter change; bleed the system fully before condemning the pump. One belt on this block often drives the fan, alternator, and water pump together, so a worn or glazed belt can starve charging and cooling at once.

Overhaul & Rebuild Points

At this displacement and output, wear margins are thin - bore, ring, and valve-seat wear cost more performance per hour than on a larger block, so track compression and blow-by rather than wait for a hard failure. Injection pump and nozzle reconditioning need a specialist familiar with this individual-pump-per-cylinder layout, not a common-rail shop. Rebuild crank and camshaft bearing clearances to print, not by eye. Given how widely the shared Yanmar block is used, a reconditioned short block or full engine swap is often the practical choice once wear is confirmed.

Seasonal & Environment Servicing

Cold starts depend on the glow plug preheat cycle, since this indirect-injection swirl-chamber design has no electronic assist - hold preheat the full cycle before cranking, and switch to the lighter cold-weather oil grade the shop manual specifies rather than running one weight year-round. Use winter-grade diesel below freezing; this small, low-pressure fuel system is prone to wax plugging in cold fuel. In dusty digging conditions, service the air cleaner element well short of the standard 250-hour mark. Coolant stays a plain water-plus-antifreeze mix; no branded formula is specified.

2D68E-3A(S/N 00101-UP) common service parts

Part numberPart
YM119255-55620Fuel Filter Ass'YCheck fitment →
YM102103-55520O-Ring,(For Fuel Filter)Check fitment →
YM124550-55700Element,Fuel FilterCheck fitment →
YM114654-55710Filter,FuelCheck fitment →
YM171051-92760Wrench,Fuel Filter? Water SeparatorCheck fitment →

Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.

2D68E-3A(S/N 00101-UP) fault codes & troubleshooting

CodeMeaningLikely causeWhat to do
Engine Oil Pressure warning lamp (oil-can symbol, red)Engine oil pressure has dropped below the safe minimumLow engine oil level, clogged oil filter or strainer, worn oil pump, or a failed pressure switch/senderStop the engine immediately, check oil level on the dipstick, inspect for leaks, and do not restart until the cause is corrected
Coolant Temperature warning lamp (thermometer symbol, red)Engine coolant temperature has exceeded the safe operating limitLow coolant level, clogged radiator fins, failed thermostat, loose or broken fan belt, or debris blocking airflowIdle down and shut off the engine, let it cool, then check coolant level and radiator for blockage before restarting
Charge (battery) warning lampAlternator is not charging the batteryLoose or broken fan/alternator belt, faulty alternator, or a loose/corroded wiring connectionCheck belt tension and battery terminal connections; have the charging circuit tested if the lamp stays on with the engine running
Glow plug / preheat indicator lamp (coil symbol)Glow plugs are energized to preheat the combustion chambers before a cold startNormal cold-start function; if the lamp fails to go out after the preheat interval, the glow plug relay or one or more glow plugs has failedWait for the lamp to go out before cranking; if it never extinguishes, have the preheat relay and glow plugs checked
Fuel level warning (low-fuel mark on gauge)Fuel level in the tank is lowTank running low during normal operationRefuel with diesel meeting the spec in the operation and maintenance manual before the tank runs dry, to avoid air entering the fuel system

Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.

2D68E-3A(S/N 00101-UP) attachments & work tools

Digging buckets

GP buckets for this micro/mini excavator class run roughly 250-450 mm (10-18 in) wide, with capacity around 0.016-0.06 m3 depending on width and the exact carrier. Bucket width and capacity scale with machine size within the class, so match the bucket to the specific model before ordering.

Hydraulic breaker (hammer)

A small-class hydraulic breaker, roughly in the 30-60 kg service-weight range, fits the arm on machines equipped with the optional auxiliary hydraulic circuit and boom-mounted piping. Breaker readiness is not standard across every unit in this class, so confirm the aux-hydraulics option is fitted before selecting one.

Coupler / mounting

Work tools mount pin-on to the arm and bucket linkage, the standard fitment method for this excavator class. No factory quick-hitch is documented as standard equipment; pin-grabber style mechanical quick couplers sized for this class are commonly added where faster tool changes are wanted.

Dozer blade

A front-mounted dozer/leveling blade is offered as factory special equipment on this size class, used for backfilling, grading and as a stabilizing outrigger while digging.

Undercarriage / track gauge

Track gauge for this size class is around 230 mm, with rubber tracks the common fitment. Some carriers in the class use a retractable or variable-width undercarriage that narrows for gate and doorway access and widens out for digging stability - verify this feature against the specific serial/model before assuming it applies.

Operator guarding

A TOPS-rated canopy is the typical operator guard fitted to this micro/mini class; a full weather cab appears further up the size range on the larger variants within the same family. Match guarding spec to the exact carrier and local safety code.

Auger drive

An auger drive unit with matched earth bits is a compatible add-on for post-hole and footing work, run off the machine's auxiliary hydraulic circuit where one is fitted. Not documented as factory-standard on the base micro-excavator configuration.

Hydraulic thumb / grapple

A hydraulic or mechanical thumb pivoting off the bucket linkage is a common fitment for grabbing and sorting material on this size class. Not listed as factory-standard equipment, but a well-established option for this bucket/arm geometry.

All 2D68E-3A(S/N 00101-UP) assemblies by section

Every catalogued assembly group for the Komatsu 2D68E-3A(S/N 00101-UP). Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.

Engine
Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Air Cleaner (Forwerded Individually Parts)
YM***00Case1
YM***80Bolt,Wing1
YM***02Nut1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Air Intake Manifold
YM***82Bolt1
YM***50Manifold,Air Intake1
YM***62Bolt Plated2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Alternator (20a) (Inner Parts)
YM***00Stator Ass'Y1
YM***02Alternator A. (20a)1
YM***00Nut,Ball1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Alternator And Mounting (20a)(#00101-10055)
YM***02Bolt Plated1
YM***02Nut1
YM***52Screw1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Alternator And Mounting (20a)(#10056-)
YM***02Bolt Plated1
YM***02Nut1
YM***50Bolt1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Camshaft And Tappet
YM***00Rod,Push4
YM***00Tappet4
YM***50Retainer, Bearing1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Crankshaft
YM***00Gear,Crank1
YM***80Bolt1
YM***41Washer1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Cylinder Block
YM***30Thrust Metal Ass'Y2
YM***00Main Metal Ass'Y (Std)3
YM***00Plug2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Cylinder Block Accsessory
YM***50Oil Pressure Transmitter1
YM***20Plug,Drain(Without Oil Cooler Type)1
YM***70Gauge,Oil Level1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Cylinder Head
YM***00Screw10
YM***00Cotter8
YM***00Plug1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Drive Gear(#00101-10055)
YM***22Retainer, Idle Gear1
YM***00Ring, Snap1
YM***52Shaft,Idler Gear1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Drive Gear(#10056-)
YM***22Retainer, Idle Gear1
YM***10Cam Ass'Y1
YM***00Ring, Snap1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Electrical Parts (Forwerded Individually Parts)
YM***21Indicator, Charging1
YM***20Timer,Solenoid1
YM***10Relay,Stop Solenoid1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Exhaust Manifold
YM***10Gasket (Kit)1
YM***00Manifold,Exhaust1
YM***22Stud4
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Flywheel And Flywheel Housing
YM***20Bolt Plated3
YM***20Parallel Pin2
YM***80Parallel Pin2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Fornt Hanger
Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Front Cover
YM***51Cap, Lub. Oil Supply1
YM***40O-Ring,Drain Plug1
YM***40O-Ring (Kit)2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Fuel Feed Pump
YM***21Feed Pump Ass'Y1
YM***50Bolt, Pipe Joint2
YM***02Seal,Ring (Kit)4
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Fuel Filter
YM***20Fuel Filter Ass'Y1
YM***40Lever1
YM***00O-Ring (Kit)1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Fuel Injection Pump (Pump) (Inner Parts)
YM***00Washer,Spring1
YM***00Washer1
YM***02Screw1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Fuel Injection Pump And Piping
YM***10Pipe,No.11
YM***10Pipe,No.11
YM***50Shim Ass'Y (Kit)1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Fuel Nozzle And Spill Hose
YM***40Spacer, Valve Stop1
YM***00Fuel Injection Valve, Assembly2
YM***80Nut1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Fuel Piping Joint
YM***00Bolt, Pipe Joint1
YM***10Filter,Fuel1
YM***02Seal,Ring (Kit)2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Gasket Kit
YM***31Gasket (Kit)1
YM***40O-Ring,Drain Plug1
YM***40O-Ring (Kit)2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Glow Plug
Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Governor(#00101-10055)
YM***30Link? 88.6mm1
YM***00Pin, Cotter1
YM***00Retainer, Shaft1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Governor(#10056-)
YM***30Link? 88.6mm1
YM***00Pin, Cotter1
YM***00Retainer, Shaft1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Head Cover
YM***00Pipe,Breather1
YM***51Cap, Lub. Oil Supply1
YM***31Gasket (Kit)1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Muffler (Forwerded Individually Parts)
Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Oil Filter
YM***50Nut1
YM***00Valve Ass'Y1
YM***50Cartridge,Engine Oil1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Oil Pan
YM***71Oil Pan Ass'Y1
YM***40Plug,Drain1
YM***52Bolt Plated16
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Oil Pump
YM***22Screw2
YM***30O-Ring (Kit)1
YM***20O-Ring,Cylinder Head Cover Bolt1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Piston And Connecting Rod
YM***00Piston Ring Ass'Y1
YM***10Bearing (--0.25 mm)1
YM***30Piston Ass'Y2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Rear Hanger
Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Rocker Arm
YM***30Screw,Adjusting2
YM***40Shaft Ass'Y1
YM***50Rocker Arm Ass'Y,Intake2
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Starting Motor (0.8kw) (Inner Parts)(#00101-10055)
YM***00Stopper Set1
YM***10Holder Brush, Assembly1
YM***70Magnetic Switch A1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Starting Motor (0.8kw) (Inner Parts)(#10056-)
YM***00Stopper Set1
YM***40Cover Ass'Y1
YM***50Brush (+)1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Starting Motor And Mounting (0.8kw)
YM***52Screw2
(Y***0)Starting Motor Ass'Y,(0.8kw) (See Fig.A6210-C0a1)1
(Y***1)Starting Motor Ass'Y,(0.8kw) (See Fig.A6210-B0a1)1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Tool
YM***60Wrench,Fuel Filter? Water Separator1
YM***50Screw Driver1
YM***51Wrench,(For Engine Oil Filter)1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Water Pump And Cooling Fan
YM***30Cover1
YM***10Tank Ass'Y,Sub1
YM***20Gasket (Kit)1
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Komatsu : 2d68e-3a(S/N 00101-Up) : Engine : Water Separator(#00101-10055)
YM***00Gasket2
YM***00O-Ring (Kit)1
YM***50Plug,Air2
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Frequently asked questions

What kind of engine is the Komatsu 2D68E-3A(S/N 00101-UP)?

It's a 2-cylinder, water-cooled, naturally aspirated diesel displacing about 0.523 L (31.9 cu in), rated 6.3-7.0 kW (8.5-9.4 HP) at 2200 rpm with a mechanical governor and no electronic engine controls. It's Komatsu's version of the Yanmar 2TNE68 block, built as part of Komatsu's 2D68E-4D88E small industrial engine range under the -3A mobile-equipment suffix, distinct from the N3-prefix stationary/generator engines in the same family.

What is the operating weight for equipment powered by this engine?

The bare engine itself isn't rated by operating weight - that spec belongs to the machine it's installed in. Komatsu's documented hosts for this exact 2D68E-3A engine, the PC03-2F, PC09-1, and PC10UU-era micro/mini excavators, run roughly 880 kg (1,940 lb) up to about 1.08 t (2,380 lb) operating weight depending on configuration and attachments. Check the specific host machine's own spec sheet for an exact figure.

What replaced the Komatsu 2D68E-3A(S/N 00101-UP)?

No single documented one-for-one successor exists for this exact engine. Komatsu kept the same 2D68E base block in parallel suffix variants (3B and 3C on the mobile-equipment side, plus separate N3-prefix codes for stationary/generator duty) rather than replacing it outright, and later, larger Komatsu mini excavators moved to different, bigger-displacement engine families entirely. Verify current parts and cross-reference status with your Komatsu dealer using the full serial number.

What 2D68E-3A(S/N 00101-UP) owners discuss

What do owners and mechanics say about the day-to-day reliability of this engine?
It's described as a simple, mechanically-governed small diesel with no electronic engine controls, part of Komatsu's small industrial engine family used across several compact excavators of this size class. General consensus among people who service these units: the core design holds up well, and most complaints trace back to neglected fuel/oil filters, old fuel, or worn injectors rather than a design flaw. Because the host machine sold in low volumes, documented long-term failure trends are thin, so treat any specific hour-count claim as anecdotal rather than confirmed.
Does this engine need glow-plug preheat before starting, especially in cold weather?
Yes. Like its sibling engines in the same small-diesel family, it starts on glow plugs since there's no electronic injection to compensate for a cold block. Field practice reported by owners is to hold preheat for roughly 20-30 seconds before cranking, longer in cold weather, and to repeat the preheat rather than grinding the starter if it doesn't fire on the first try. A weak glow plug or bad relay typically shows up first as a cold engine that's harder to start each time temperatures drop, well before it fails to run once warm.
The engine only starts with starting fluid and then dies - what's the usual community diagnosis?
This pattern is treated as a fuel-delivery problem first on these small mechanical-injection Komatsu diesels, not an ignition or compression problem. The checklist owners and shops report working through: verify the shutoff solenoid on the injection pump is energizing (a known point that cuts fuel delivery entirely when it fails), confirm the transfer pump is actually moving fuel by testing at the primer inlet, and bleed the fuel system fully since trapped air after a filter change or a long idle period is a frequent cause. Have your dealer or a qualified diesel shop verify injection pump timing and solenoid function before condemning the pump itself.
What does it mean if the engine stalls and puts out white smoke?
Owners and mechanics treat stalling plus white smoke as a sign of coolant reaching the combustion chamber or incomplete combustion, not something to just top off and keep running. Reported troubleshooting order: check coolant level and look for external leaks, inspect for a blown head gasket or cracked cylinder head, and check injector condition. Smoke or pressure showing up at the dipstick or oil-fill cap is called out specifically as pointing toward a blown gasket or a holed piston rather than a simple fuel-mixture issue. Because this points at internal engine damage, have your dealer verify with a compression test before committing to teardown.
Do owners report hydraulic issues that only show up after the machine has warmed up?
Yes, and it's a pattern reported across small/compact Komatsu excavators generally, not unique to one exact host machine: the machine moves fine cold, then after an hour or two of work the boom and controls go sluggish and pump or valve noise picks up. Community diagnosis points to internal pump or valve leakage, worn spool seals, or degraded/contaminated hydraulic fluid rather than one single common failure point. On these compact, tightly packaged machines, owners also note that pressure test ports can be hard to reach, which complicates self-diagnosis - fluid condition and cleanliness get flagged repeatedly as the first thing to rule out.
What undercarriage or track wear patterns should owners watch for on this size of machine?
This class of mini excavator typically rides on rubber tracks rather than steel-shoe chains, and the wear signs owners watch for match other small rubber-tracked machines: cracking or ripping in the rubber, noticeably shallower tread/lug depth, and a track that's gone loose on the frame. A loose-looking track isn't automatically worn out - low track tension or grease is flagged as the first thing to check before assuming the track itself needs replacement. Rollers and idlers get checked for play or flat spots at the same time since they wear in step with the track.
What should a buyer check before purchasing a used machine with this engine?
This size of Komatsu mini excavator/power shovel sold in low volumes, and many examples on the used market elsewhere arrived as grey-market Japan-domestic imports, so the buyer checklist reported by owners and inspectors repeats a few points: get the full serial number and call a Komatsu dealer with it before buying, since dealers can generally still source parts once the machine is correctly identified, sometimes special-ordered with a multi-week wait. Confirm the machine carries the safety equipment expected for where it will be used (rollover protection, backup alarm, warning decals), since grey-market units sometimes lack these. Budget for a paid pre-purchase inspection by an independent diesel/heavy-equipment mechanic covering compression, hydraulic pressures, and hour-meter consistency rather than relying on the seller's description. Have your dealer verify the serial number, engine identity, and safety-equipment compliance before finalizing the purchase.

Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.

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