The Kohler 125REOZJG is a 125-kilowatt diesel commercial standby generator powered by a John Deere engine at 1800 RPM. It uses a brushless rare-earth permanent-magnet alternator with Fast-Response excitation and sustained short-circuit capability up to 300% of rated current for 10 seconds. The unit features integrated environmental containment and is available in sound-attenuated enclosure configurations rated at 71 dB(A) at 7 meters.
OnPoint services mid-range diesel standby generators throughout Northern California for hospitals, schools, and commercial facilities. The John Deere engine platform in the 125REOZJG shares commonality with the 80REOZJF and 100REOZJF, simplifying parts stocking and technician training across the REOZJ series.
Tell us about the application — kW, voltage, application, install timeline — and we'll respond within one business day with budgetary pricing, lead time, and any sizing notes.
Adjust load percent and tank size to estimate runtime. Pre-filled with this model's spec where available.
Estimate runtime on this tank
Estimated runtime
26.2 hours(1.1 days)
Fuel consumption ≈ 7.64 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 125REOZJG 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
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 is in the Kohler 125REOZJG?
The 125REOZJG uses a John Deere diesel engine, turbocharged and aftercooled, rated at 1800 RPM for stationary emergency standby use.
What sound level does the 125REOZJG produce?
Per Kohler specifications, the 125REOZJG is rated at 71 dB(A) at 7 meters at full load with the sound-attenuating enclosure.
Does the 125REOZJG include fuel containment?
Yes. The unit includes a 125% oil/coolant containment basin and 110% secondary fuel containment tank with 24-hour runtime capability at prime rating.
THD below 3% at 130 kW -- the healthcare and commercial default. John Deere 6068HG550 with Decision-Maker controller.
130 kW standby · Diesel · Liquid-cooled
130 kW commercial standby for hospitals, schools, retail, and institutional facilities requiring clean power and NFPA 110 compliance.
130 kW diesel commercial standby generator powered by John Deere. Reliable standby power for commercial and institutional facilities.
Tier 4 Final3-phasecommercialhealthcare
Kohler
Kohler 145REOZT4
130 kW mobile diesel trailer -- Tier 4 John Deere 6068HG550. DOT-towable for large temporary power and emergency deployment.
130 kW standby · Diesel · Liquid-cooled
130 kW mobile standby for large construction projects, event power, emergency response, and planned outage bridge power.
130 kW diesel mobile trailer Tier 4 Final commercial standby generator powered by John Deere. Reliable standby power for commercial and institutional facilities.
Tier 4 Final3-phasecommercialhealthcare
Kohler
Kohler 100REOZJF
THD below 3% at 100 kW -- the healthcare and commercial default. John Deere 4045HF285 with Decision-Maker controller.
100 kW standby · Diesel · Liquid-cooled
100 kW commercial standby for hospitals, schools, retail, and institutional facilities requiring clean power and NFPA 110 compliance.
100 kW diesel commercial standby generator. Mid-range diesel workhorse for commercial facilities, healthcare, and institutional applications.
Tier 33-phasecommercialhealthcare
Need service or parts for the Kohler 125REOZJG?
We service every major OEM and stock genuine parts for the most common models.
