Home›Engines›Katolight 6125HF070

Katolight 6125HF070 Engine

The Katolight 6125HF070 is a 7.66 L 6-cylinder turbocharged ~ air to air intercooled engine rated at 1800 rpm. It powers generator sets from Katolight, including the D415FGJ4, D415FJJ4, D415FNJ4 and D415FPJ4. It holds 42 L (11.1 gal) of oil and 16.2 L (4.3 gal) of coolant.

Also known as: Katolight 6125HF070

7.66 L

Displacement

Cylinders

1800 rpm

Rated speed

42.0 L

Oil capacity

On this pageSpecs Generator sets FAQ Service intervals Torque & specs Fluids Fault codes Procedures Wiring

Engine specifications

Oil capacity	42.0 L
Coolant capacity	16.2 L
Displacement	7.66 L
Cylinders	6
Aspiration	Turbocharged ~ Air to Air Intercooled
Rated speed	1800 rpm

Generator sets powered by this engine

Katolight D415FGJ4 Katolight D415FJJ4 Katolight D415FNJ4 Katolight D415FPJ4 Katolight D415FRJ4

Common problems

Excessive Oil Consumption
Cause: Too low viscosity crankcase oil
Fix: Drain crankcase and refill with correct viscosity oil.
Abnormal Engine Noise
Cause: Worn main or connecting rod bearings
Fix: Determine bearing clearance. See your John Deere engine distributor or servicing dealer.
Low Oil Pressure
Cause: Low crankcase oil level
Fix: Fill crankcase to proper oil level.
Generator produces no voltage or residual voltage
Cause: Regulator Fuse Blown
Fix: Check fuse with an ohmmeter. Replace bad fuse, refer to regulator manual.
Engine Overheats
Cause: Lack of coolant in cooling system
Fix: Fill cooling system to proper level.
Generator produces low voltage - no load
Cause: Underspeed Operation
Fix: Check speed using tachometers and/or frequency meters.
Coolant in Crankcase
Cause: Cylinder head gasket defective
Fix: Replace cylinder head gasket. See your John Deere engine distributor or servicing dealer.
Oil in Intake Manifold or Dripping from Turbocharger Housing
Cause: Excessive crankcase pressure
Fix: Determine cause of excessive crankcase pressure; repair as required. See your John Deere engine distributor or servicing dealer.
Generator voltage is fluctuating
Cause: Incorrect Speed
Fix: Verify speed with tachometer or frequency meter.
Generator produces high voltage
Cause: Defective Voltmeter
Fix: Verify operation of panel meter with another meter that is known to be accurate. Refer to section 8.
High Oil Pressure
Cause: Improper oil classification
Fix: Drain crankcase and refill with correct oil.
Lack of Engine Power
Cause: Poor fuel quality
Fix: Drain fuel and replace with quality fuel of the proper grade.
Hard to Start or Will Not Start
Cause: Poor fuel quality
Fix: Drain fuel and replace with quality fuel of the proper grade.
Excessive Fuel Consumption
Cause: Poor fuel quality
Fix: Drain fuel and replace with quality fuel of the proper grade.
Engine Will Not Crank
Cause: Weak battery
Fix: Replace battery.

Compiled from service & troubleshooting documentation across every generator set that uses the Katolight 6125HF070.

Service intervals

Item	Action	Hours	Months	Notes
Fire extinguisher	Inspect	100 hr	1 mo	At least every 100 hours of engine operation or once a month; recharge once operated
Battery	Test	250 hr	6 mo	Check electrolyte level, clean and tighten connections, keep fully charged
Coolant pump weep hole foam filter	Check	250 hr	6 mo
Engine mounts (generator sets)	Check	250 hr	6 mo	Use only Grade SAE 8 or higher hardware
Engine oil and oil filter	Change	250 hr	6 mo	Change first at 100 hours maximum (break-in), then every 250 hours; may extend 50% to 375 hours with PLUS-50 or ACEA-E4/E5 oil plus John Deere filter
Air intake hoses, connections & system	Check	500 hr	12 mo	Inspect hoses for cracks; tighten clamps
Automatic belt tensioners and belt wear	Inspect	500 hr	12 mo	Upper spring tension 18-23 Nm (13-17 lb-ft); lower spring tension 81-99 Nm (60-73 lb-ft)
Coolant solution analysis; add SCAs as required	Test	500 hr	12 mo	Test at 500 hours or 12 months; test at 12 months or less in general
Cooling system	Check	500 hr	12 mo	Check for leaks; inspect hoses for hard, flimsy or cracked condition
Cooling system and radiator cap	Test	500 hr	12 mo	Pressure test to 48 kPa (0.48 bar) (7 psi)
Crankcase ventilation assembly	Clean	500 hr	12 mo	Inspect and clean; replace O-rings as necessary
Engine ground connection	Check	500 hr	12 mo	Must be tight and clean to prevent electrical arc
Cooling system	Drain	2000 hr	24 mo	Flush and refill; with John Deere COOL-GARD extend to 3000 hours/36 months, or 5000 hours/60 months if tested annually and additives replenished
Crankshaft vibration damper	Check	2000 hr	24 mo	Replace at 4500 hours or 60 months, whichever occurs first
Thermostats	Test	2000 hr	24 mo	Opening temperature 80-84 C (175-182 F); full open 94 C (202 F)
Engine valve clearance and EUI preload	Adjust	2500 hr		First service — One-time adjustment after first 2500 hours on all new and overhauled engines; by John Deere dealer
Fuel filter element / clean water separator	Replace		12 mo	As required when alarm/trouble code indicates plugged filter; otherwise every 12 months or 500 hours

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Service specifications

Type	Item	Value	Unit	Condition
Clearance	Crankshaft vibration damper maximum radial runout	0.76	mm	0.030 in; engine at operating temperature
Pressure	Cooling system test pressure	48	kPa	0.48 bar (7 psi); engine warmed up
Pressure	Engine oil pressure, full load rated speed	310 +/- 103	kPa	45 +/- 15 psi at 1500-2100 rpm, oil at 115 C (240 F)
Pressure	Engine oil pressure, low idle (minimum)	138	kPa	1.38 bar (20 psi) minimum
Pressure	Maximum air intake restriction	25	in. H2O	625 mm H2O (6.25 kPa) (0.06 bar) (1.0 psi)
Pressure	Maximum crankcase pressure	0.5	kPa	2 in. H2O
Pressure	Radiator cap test pressure	48	kPa	0.48 bar (7 psi); gauge should hold 10 seconds
Speed	Engine overspeed shutdown	66	Hz	Diesel units (71 Hz for gas units)
Speed	Generator speed / frequency relationship	1800	RPM	60 Hz at 1800 rpm, 1500 rpm for 50 Hz; Hz x 30 = RPM
Speed	Starter crank disconnect speed	500-750	RPM	Starter disconnects when engine reaches this speed
Temperature	Engine coolant temperature range	82-94	C	180-202 F; derate at approximately 100 C (212 F)
Temperature	Thermostat start-to-open temperature	80-84	C	175-182 F; full open 94 C (202 F)
Torque	Air filter restriction indicator/retaining nut	14	Nm	10 lb-ft
Torque	Cable connector (wiring lug), 1/4 in. socket	200	in-lb	across flats 1/4 in.; TQD, TQDL
Torque	Cable connector (wiring lug), 3/8 in. socket	375	in-lb	across flats 3/8 in.
Torque	Cable connector (wiring lug), 5/16 in. socket	275	in-lb	across flats 5/16 in.
Torque	Crankcase vent baffle-to-rocker arm cover cap screws	15	Nm	11 lb-ft (133 lb-in)
Torque	E150 line lug mounting	30	in-lb	minimum
Torque	F225 line lug mounting	90	in-lb	minimum
Torque	J600 line lug mounting	60	in-lb	minimum
Torque	K1200 line lug mounting	200	in-lb	minimum
Torque	Lower belt tensioner spring tension	81-99	Nm	60-73 lb-ft; align marks 25 mm (1.0 in.) apart
Torque	Oil drain plug (1-1/2 in.)	64	Nm	47 lb-ft
Torque	Oil drain plug (1-1/4 in.)	46	Nm	34 lb-ft
Torque	Shunt trip locknut (GE shunt trip accessory)	6	in-lb	tighten against plunger to prevent loss of adjustment
Torque	Thermostat cover long cap screws	50	Nm	37 lb-ft
Torque	Thermostat cover short cap screws	35	Nm	26 lb-ft
Torque	Upper belt tensioner spring tension	18-23	Nm	13-17 lb-ft; align marks 21 mm (0.83 in.) apart
Torque	Water separator bowl-to-filter housing	5	Nm	44 lb-in; hand tighten until seal contacts
Voltage	High engine temperature / low oil pressure fault switch thresholds (controller displays)	225 F / 15 psi		High engine temp shutdown above 225 F (107 C); pre-alarm 215 F (102 C); low oil pressure shutdown 15 psi (103 kPa); pre-alarm 20 psi (138 kPa)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

Fluid	Grade	Standard	Ambient	Capacity	Notes
Coolant	John Deere COOL-GARD Prediluted Coolant	ASTM D6210; low silicate ethylene/propylene glycol, 40 to 60% concentrate with quality water	above -37°C	104.5 L	50% ethylene glycol gives freeze protection to -37 C (-34 F); 50% propylene glycol -33 C (-27 F). System filled to -37 C (-34 F). Do not use automotive-type coolants (ASTM D3306/D4656)
Engine oil	John Deere Engine Break-In Oil				Factory fill; order TY22041. Do not exceed 100 hours of operation with break-in oil. Do not use PLUS-50 or CI-4/CH-4/E4/E5 oils during first 100 hours
Engine oil	SAE 0W-40	API CI-4 / CH-4; ACEA E4/E5			Listed in engine oil viscosity chart
Engine oil	SAE 10W-40	API CI-4 / CH-4; ACEA E4/E5			Listed in engine oil viscosity chart
Engine oil	SAE 15W-40	John Deere PLUS-50 (preferred); TORQ-GARD SUPREME; API CI-4 / CH-4; ACEA E4/E5 or E3		40.0 L	Select viscosity from the printed viscosity/temperature chart. Multi-viscosity oils preferred. Reduce oil/filter interval by 100 hours with fuel sulfur above 0.05% (500 ppm)
Engine oil	SAE 5W-30	API CI-4 / CH-4; ACEA E4/E5			Listed in engine oil viscosity chart
Fuel	Diesel, Grade No. 1-D for cold weather below 5 C (40 F)	EN 590 or ASTM D975			Cetane number 45 minimum, 50 preferred below -20 C or above 1500 m. Sulfur less than 0.05% (500 ppm) preferred; do not use above 1.0%. Do not mix used engine oil with diesel fuel. Bio-diesel only per ASTM PS121 / DIN 51606, up to 5% blend
Grease	John Deere SD POLYUREA GREASE R220 (preferred)	NLGI Performance Classification GC-LB			Also HD MOLY, HD LITHIUM COMPLEX, HD WATER RESISTANT, GREASE-GARD. Generator bearings: Cheveron SRI or equivalent, range -30 to +175 C (-22 to +350 F)
Other	John Deere LIQUID COOLANT CONDITIONER (supplemental coolant additive)				Replenish every 12 months or as determined by coolant testing; 3% by total system capacity for pre-charge; do not mix brands

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Fault codes

Code	Name	Meaning	Severity	Action
1	Fallo presión de aceite	LED rojo (R) de visualización	Shutdown
2	Fallo temperatura de agua	LED rojo (R) de visualización	Shutdown
3	Fallo no arranque	LED rojo (R) de visualización	Shutdown
4	Fallo sobrevelocidad	LED rojo (R) de visualización	Shutdown
5	Grupo listo para suministrar	LED verde (V) de visualización	Info
6	Fallo alternador de carga	LED rojo (R) de visualización	Shutdown
7	Alarma general	LED amarillo (A) de visualización	Warning
8	Fallo general	LED rojo (R) de visualización	Shutdown
627/01	Injector Supply Voltage Problem	Injector supply voltage problem	Warning	Contact your John Deere distributor or servicing dealer
629/13	ECU Error	Engine control unit error	Warning	Contact dealer
636/02	Cam Position Input Noise	Camshaft position sensor input noise	Warning	Inspect sensor and wiring; contact dealer
636/08	Cam Position Input Missing	Camshaft position input missing	Shutdown	Inspect sensor and wiring; contact dealer
636/10	Cam Position Input Pattern Error	Camshaft position input pattern error	Warning	Contact dealer
637/02	Crank Position Input Noise	Crankshaft position sensor input noise	Warning	Inspect sensor and wiring; contact dealer
637/07	Crank Position/Cam Position Out of Sync	Crankshaft and camshaft position out of synchronization	Shutdown	Contact dealer
637/08	Crank Position Input Missing	Crankshaft position input missing	Shutdown	Contact dealer
637/10	Crank Position Input Pattern Error	Crankshaft position input pattern error	Warning	Contact dealer
639/13	CAN (Network) Error	Control Area Network communication error	Warning	Inspect CAN wiring and connectors; contact dealer
651/05	Cylinder #1 EUI Circuit Open	Cylinder 1 electronic unit injector circuit open	Shutdown	Contact dealer
651/06	Cylinder #1 EUI Circuit Shorted	Cylinder 1 electronic unit injector circuit shorted	Shutdown	Contact dealer
652/05	Cylinder #2 EUI Circuit Open	Cylinder 2 electronic unit injector circuit open	Shutdown	Contact dealer
652/06	Cylinder #2 EUI Circuit Shorted	Cylinder 2 electronic unit injector circuit shorted	Shutdown	Contact dealer
653/05	Cylinder #3 EUI Circuit Open	Cylinder 3 electronic unit injector circuit open	Shutdown	Contact dealer
653/06	Cylinder #3 EUI Circuit Shorted	Cylinder 3 electronic unit injector circuit shorted	Shutdown	Contact dealer
654/05	Cylinder #4 EUI Circuit Open	Cylinder 4 electronic unit injector circuit open	Shutdown	Contact dealer
654/06	Cylinder #4 EUI Circuit Shorted	Cylinder 4 electronic unit injector circuit shorted	Shutdown	Contact dealer
655/05	Cylinder #5 EUI Circuit Open	Cylinder 5 electronic unit injector circuit open	Shutdown	Contact dealer
655/06	Cylinder #5 EUI Circuit Shorted	Cylinder 5 electronic unit injector circuit shorted	Shutdown	Contact dealer
656/05	Cylinder #6 EUI Circuit Open	Cylinder 6 electronic unit injector circuit open	Shutdown	Contact dealer
656/06	Cylinder #6 EUI Circuit Shorted	Cylinder 6 electronic unit injector circuit shorted	Shutdown	Contact dealer
970/02	Auxiliary Engine Shutdown Switch Signal Invalid	Auxiliary engine shutdown switch signal invalid	Warning	Inspect auxiliary shutdown switch wiring; contact dealer
970/31	Auxiliary Engine Shutdown Switch Active	Auxiliary engine shutdown switch active	Shutdown	Determine why shutdown switch activated; contact dealer
971/31	External Fuel Derate Switch Active	External fuel derate switch active	Warning	Investigate derate switch activation; contact dealer
1109/31	Engine Shutdown Warning	Engine shutdown warning condition present	Warning	Contact dealer
1110/31	Engine Shutdown	Engine shutdown condition present	Shutdown	Contact dealer
1569/31	Fuel Derate	Fuel derate condition present	Warning	Contact dealer
2000/13	Security Violation	Security violation	Warning	Contact dealer

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

Testing Thermostats Opening Temperature diagnostic

⚠ Do not allow thermostat or thermometer to rest against side or bottom of container

Tools: Thermometer, Container

Remove radiator cap and partially drain cooling system.
Remove four cap screws and thermostat cover.
Remove gasket and both thermostats.
Inspect thermostats for corrosion or damage.
Suspend thermostat and thermometer in water and heat.
Stir water, observe opening action against specification.
Observe closing action as it cools; replace as matched set.

Bleeding Fuel System maintenance

Drain water from clear separator sediment bowl via drain valve.
Attach open line to diagnostic port, place end in container.
Pump hand primer until steady flow without bubbles.
Disconnect line from diagnostic port.
Start engine and run for five minutes.

Changing Engine Oil and Replacing Oil Filter maintenance

⚠ Metal surfaces may be hot after shutdown

⚠ Do not overfill; fill within crosshatch on dipstick

Tools: Filter wrench, Torque wrench

Run engine about 5 minutes to warm oil, then shut off.
Remove oil pan drain plug and drain oil while warm.
Remove and discard oil filter element using filter wrench.
Remove packing, clean filter mounting pad.
Oil new packing, install new element, tighten 1/2-3/4 turn by hand.
Install drain plug with new O-ring; torque 46 Nm (34 lb-ft).
Fill crankcase with correct John Deere engine oil.
Crank engine 30 seconds without starting; run and check leaks.

Replacing Air Cleaner Filter Elements maintenance

⚠ Do not clean, wash or reuse the secondary element

Remove wing nut, canister cover and primary filter assembly.
Thoroughly clean all dirt from inside canister.
Squeeze dust unloader valve to remove dust.
Replace secondary element only if green dot disappeared.
Install new primary element and tighten wing nut securely.
Depress air restriction indicator reset button if equipped.

Replacing Fan/Alternator V-Belts maintenance

Tools: 3/4-in. breaker bar (lower), 1/2-in. breaker bar (upper)

Release tension on lower belt with breaker bar in tensioner.
Remove V-belt from pulleys and discard.
Install new belt correctly seated in all pulley grooves.
Release tensioner to apply tension; remove ratchet.
Lower V-belt must be removed before upper V-belt.
Check belt alignment; start engine and visually recheck.

Replacing Fuel Filter / Cleaning Water Separator maintenance

⚠ Engine and fuel filter housing may be hot

Tools: Strap wrench

Close fuel shut-off valve, clean area around filter.
Remove cap from fuel filter housing.
Operate hand primer until filter pops up to relieve vacuum.
Remove and drain filter element into suitable container.
Remove and clean water separator bowl with strap wrench.
Install new dry fuel filter into housing.
Reinstall cap hand-tight; open fuel shut-off valve.
Restart engine and run five minutes minimum.

Automatic Operation Sequence operation

Leave engine control in AUTO position.
Leave generator circuit breaker in ON position.
On power failure remote start contact closes, engine starts.
Set reaches speed and voltage, then transfers load.
On power return load retransfers after time delay.
Remote start contact opens; unit shuts down.

Emergency Stop (optional equipment) operation

⚠ This stops and locks out the generator set

Push red mushroom head emergency stop button.
Pull button out to reset and extinguish red light.
Place engine control in OFF to reset.
Reset main line circuit breaker before AUTOMATIC operation.

Manual Shutdown operation

Open generator circuit breaker, move handle DOWN.
Place engine control in OFF position.
For automatic operation reset breaker handle to UP.

Manual Start operation

⚠ Check operator's manual if engine does not start

Ventilate the space or open doors and windows.
Open the generator circuit breaker.
Place engine control in MANUAL/RUN position.
Check frequency; 60 Hz rated speed within 3-5%.
Check AC voltage and engine parameters on gauges.
Close the generator circuit breaker.

Starting the Engine operation

⚠ Install proper exhaust ventilation before starting in a confined building

Perform all daily prestarting checks.
Open the fuel supply shut-off valve, if equipped.
Disengage power to any engine drivelines.
Set slow idle using speed select switch.
Turn key start switch clockwise to crank engine.
After start, idle at not more than 1200 rpm until warm.
Check all gauges for normal operation.

Stopping the Engine operation

⚠ Ensure exhaust stack rain cap is installed when engine is not running

Disengage PTO clutch lever, if equipped.
Run engine at 1000-1200 rpm for at least 2 minutes.
Set slow idle speed.
Turn key start switch to OFF and remove key.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

Voltage	Phase	Connection	Leads	Notes
120 (240 L-L)	3	12 lead low delta	12	Delta connection with 12 lead generators only
120/240	1	12 lead zig-zag	12	Zig-zag connection with 12 lead machine only; used for the single-phase D415FGJ4 model
208/120 (also 190/110)	3	10 lead low wye	10 or 20 cables	One end of three inner coils connected together
208/120 (also 220/127, 230/133, 240/139)	3	12 lead low wye	12 or 24 cables	Dual voltage, six coils
240 (also 480)	3	6 lead delta	6 or 12 cables	Six lead generators have 3 coil groups
240/120 (also 190/110, 208/120, 220/127, 230/133)	3	6 lead wye	6 or 12 cables or bus bars	Six lead generators have 3 coil groups
240/120 (also 200/100, 220/110)	3	12 lead hi delta	12	Delta connection with 12 lead generators only
480 (also 240)	3	3 lead delta	3, 6 or 12 cables or 3 bus bars	One end of each coil group connected into a delta internally
480/277 (also 380/219, 400/231, 416/240, 440/254, 460/266)	3	10 lead hi wye	10 or 20 cables	One end of three inner coils connected together
480/277 (also 380/219, 400/231, 416/240, 440/254, 460/266)	3	12 lead hi wye	12 or 24 cables	Dual voltage, six coils; two reconnect voltage ranges (high/low)
480/277 (also 380/219, 400/231, 416/240, 440/254, 460/266, 600/346)	3	4 lead wye	4, 8 or 16 cables or 4 bus bars	One end of each of the 3 coil groups connected together

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What is the oil capacity of the Katolight 6125HF070?

The Katolight 6125HF070 engine has an oil capacity of 42.0 liters.

What is the displacement of the Katolight 6125HF070?

The Katolight 6125HF070 has a displacement of 7.66 liters with 6 cylinders.

Which generators use the Katolight 6125HF070 engine?

The Katolight 6125HF070 powers 5 generator set(s), including Katolight D415FGJ4, Katolight D415FJJ4, Katolight D415FNJ4, Katolight D415FPJ4, Katolight D415FRJ4.

What is a common problem with the Katolight 6125HF070 engine?

A commonly reported issue on generators using the Katolight 6125HF070 is: Excessive Oil Consumption. Cause: Too low viscosity crankcase oil. Fix: Drain crankcase and refill with correct viscosity oil..