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Home›Cummins/Onan›Cummins/Onan 4.0 KY

Cummins/Onan 4.0 KY Generator Set

The Cummins/Onan 4.0 KY is a 4 kW (4000 kVA) gasoline standby generator set. It is available at 120 V, 1-phase, 60 Hz and rated 33.3 A. It holds about 1.5 L (0.4 gal) of oil. Starting uses 1 battery rated 360 CCA at 12 V. The set weighs about 78 kg (172 lb).

4 kW
Standby
1.5 L
Oil capacity
3
Document types

How to read your Cummins/Onan serial & model number →

Specifications

Fuelgasoline
Frequency60.0 Hz
Standby power4 kW
Prime power4 kW
EmissionsEPA PH1 and California 1995-1998
Oil capacity1.5 L
Voltage options120 V
Phase1
Rated current33.3 A
Battery cranking360 CCA
Battery voltage12 V
Battery quantity1
Dry weight78 kg

Filters & service parts

model family
ItemSpecCapacityPart #Interval
Air filterEngine air filter—1000 hr find
Fuel filter—500 hr find
Oil filter—1000 hr find
Belt—1000 hr find
Coolant—5000 hr
OilAPI Class SG or SH (SG/CD, SG/CE, SH/CD, SH/CE)1.6 liters15W4050 hr eBay $35.16

Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number.

Common questions

What is the power rating of the Cummins/Onan 4.0 KY?

The Cummins/Onan 4.0 KY is rated 4 kW standby.

What fuel does the Cummins/Onan 4.0 KY use?

The Cummins/Onan 4.0 KY runs on gasoline.

Troubleshooting

5

Symptoms & remedies

SymptomRemedy
DizzinessGET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired.
Muscular TwitchingGET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired.
VomitingGET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired.
Weakness and SleepinessGET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired.
Inability to Think CoherentlyGET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the genset and do not operate it until it has been inspected and repaired.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.

Parts

4model family
Part #DescriptionQtySystem
539-1546Compartment floor plan template1Service part / kit buy
611-1245Voltage Reconnection DiagramService part / kit buy
611-1246Voltage Reconnection DiagramService part / kit buy
M1742Splash guards1Service part / kit buy

Compiled from this model's family documentation — may include parts for closely-related variants. Confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Fuel consumption

RatingLoadL/hgal/h
1.10.29
50%1.70.44
100%2.70.71
Prime
Prime1.10.29
Prime50%1.70.44
Prime100%2.70.71
Standby

Available documents

Operator's manualOwner's manualService manual