What engine powers the Kohler 125REOZJ4?

The 125REOZJ4 uses a John Deere diesel engine running at 1800 RPM (model 6068HG550).

What is the standby power rating of the 125REOZJ4?

The 125REOZJ4 is rated at 130 kW standby and 117 kW prime per Kohler published specifications.

Does OnPoint service the Kohler 125REOZJ4?

Yes. OnPoint Generators provides maintenance, repair, and load bank testing for Kohler REOZ diesel generators throughout Northern California, including the 130 kW class.

Kohler · REOZ Series (Diesel Commercial Standby)

Kohler 125REOZJ4

130 kW standby / 117 kW prime · Diesel · Liquid-cooled

130 kW diesel commercial standby generator powered by John Deere. Reliable standby power for commercial and institutional facilities.

Standby power: 130 kW / 117 kW prime
Voltage options: 277/480V, 120/208V, 120/240V
Frequency / Phase: 60 Hz · 1/3-phase
Engine: John Deere 6068HG550 · 6.8L
EPA / Emissions: Tier 4 Final
Alternator: Kohler 4R13X

Commercial Healthcare Governmentindustrial-light

Overview#

The Kohler 125REOZJ4 is a 130-kilowatt standby (117 kW prime) diesel generator powered by a John Deere engine at 1800 RPM. Typical applications include commercial buildings, healthcare, and institutional facilities.

Our service experience#

OnPoint Generators services Kohler REOZ diesel generators throughout Northern California. We typically structure service for this class around annual NFPA 110 maintenance plus semi-annual fuel quality and filter inspections.

Engineering specifications

Physical

Length: 139 in
Width: 46.9 in
Height: 89.6 in
Wet weight: 7,719 lb

Acoustic

Sound @ 7m, full load: 70 dBA
Enclosure: Sound-attenuated

Fuel system & runtime

Integral fuel tank: 244 gal
Fuel use @ full load: 9.4 GPH
Fuel use @ 75% load: 7.2 GPH
DEF tank: 11.7 gal

Photos

Documents & downloads

Spec sheets & manuals

Spec sheet (datasheet)

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Estimate runtime for the Kohler 125REOZJ4

Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.

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Generator size

Fuel

Fuel tank capacity

gal

Load

Override full-load GPH (optional)

GPH

Estimated runtime

33.6 hours(1.4 days)

Fuel consumption ≈ 7.25 GPH at 75% load. Estimate based on industry-typical 1800 RPM standby curves (≈0.07 GPH/kW at full load). Actual consumption varies by engine, ambient temperature, fuel quality, and tuning.

Service intervals

Manufacturer-recommended intervals for the Kohler 125REOZJ4 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.

Oil & filter: Every 250 hours or 12 months
Coolant change: Every 3000 hours
Air filter: Every 500 hours
Fuel filter: Every 500 hours
Major overhaul: ≈ 15,000 hours
Load bank test: Every 12 months

Common failure modes

What we've seen fail on this platform. Use as a service-planning reference, not a diagnostic — actual failure modes depend heavily on duty cycle and maintenance history.

Component	Symptom	Typical hours	Severity
DEF system (SCR catalyst)	Derate warning, NOx fault, DEF quality alert	4,380+	moderate
Fuel quality / degradation	Injector fouling, hard starting, filter clogging	4,380+	moderate
Turbocharger	Power loss, excessive smoke under load	12,000+	moderate
Battery (starting)	Failed to start, slow crank	8,760+	minor

Frequently Asked Questions

What engine powers the Kohler 125REOZJ4?: The 125REOZJ4 uses a John Deere diesel engine running at 1800 RPM (model 6068HG550).
What is the standby power rating of the 125REOZJ4?: The 125REOZJ4 is rated at 130 kW standby and 117 kW prime per Kohler published specifications.
Does OnPoint service the Kohler 125REOZJ4?: Yes. OnPoint Generators provides maintenance, repair, and load bank testing for Kohler REOZ diesel generators throughout Northern California, including the 130 kW class.

Compatible equipment

Transfer switches

More in the REOZ Series (Diesel Commercial Standby)

Kohler's diesel commercial standby series — 10 to 510 kW, John Deere and Kohler engines, built for life-safety loads.

View all 33models in this series →

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