1250 kW EPA Tier 4 Final diesel industrial standby generator. Dual-certified (emergency and non-emergency) for mission-critical and prime power applications.
The Kohler KD1250-4 is a 1250-kilowatt EPA Tier 4 Final diesel industrial generator from Kohler's KD Series platform. The -4 designation indicates Tier 4 Final emissions compliance with dual certification for both emergency standby and non-emergency (prime power) applications. This makes the KD1250-4 suitable for installations where air quality district rules require Tier 4 compliance or where continuous/prime duty is needed. The KD Series uses Kohler-designed engines and permanent-magnet pilot exciter alternators.
The KD Series is Kohler's large industrial diesel generator line, covering 800 to 4000 kW. Designed for mission-critical facilities, every KD Series unit carries UL 2200 listing and meets NFPA 110 Level 1 requirements when equipped with the necessary accessories. Hurricane-rated enclosures with 186 mph wind load ratings are available across the platform.
OnPoint Generators provides installation, maintenance, and emergency service for Kohler KD Series generators throughout Northern California. Tier 4 Final units require additional aftertreatment system maintenance, including DEF management and DPF regeneration monitoring, which our technicians handle as part of comprehensive PM programs.
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
3.0 hours(0.1 days)
Fuel consumption ≈ 67.50 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 KD1250-4 under standby duty. Field intervals may differ based on load profile, ambient conditions, and fuel quality.
Oil & filter
Every 500 hours or 12 months
Coolant change
Every 6000 hours
Air filter
Every 1000 hours
Fuel filter
Every 500 hours
Major overhaul
≈ 20,000 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
DPF (Diesel Particulate Filter)
Regen warning, back-pressure fault, power derate
4,380+
moderate
DEF system (SCR catalyst)
Derate warning, NOx fault, DEF quality alert
4,380+
moderate
Fuel quality / degradation
Injector fouling, hard starting, black smoke under load
4,380+
moderate
Turbocharger
Power loss, excessive exhaust smoke, oil at turbo seals
15,000+
moderate
Cooling system (hoses / thermostat)
Overtemperature fault, coolant loss, high EGT
10,000+
moderate
Battery (starting)
Slow crank, failed exercise, low voltage alarm
8,760+
minor
Frequently Asked Questions
What is the standby rating of the Kohler KD1250-4?
Per the Kohler spec sheet, the KD1250-4 is rated at 1250 kW / 1562 kVA standby and 1130 kW / 1412 kVA prime continuous at 0.8 power factor, 60 Hz, 1800 RPM.
Is the Kohler KD1250-4 EPA Tier 4 certified?
Yes. The KD1250-4 is EPA Tier 4 Final certified with dual certification for both stationary emergency and stationary non-emergency applications, making it suitable for prime power duty where air quality regulations require Tier 4 compliance.
What alternator type does the KD1250-4 use?
The KD1250-4 uses a brushless, permanent-magnet pilot exciter alternator — Kohler's standard for the KD Series large industrial diesel platform.
Similar models
Kohler
New
Kohler KD1250-A
1.3 MW standby · Diesel · Liquid-cooled
1250 kW diesel industrial standby generator. KD Series platform for data centers, healthcare, and large commercial facilities.
Tier 23-phasedata-centerhealthcare
Kohler
New
Kohler 1250REOZMD
1.3 MW standby · Diesel · Liquid-cooled
1280 kW diesel industrial generator powered by Mitsubishi. Mission-critical standby for data centers, hospitals, and large commercial facilities.
Tier 23-phasedata-centerhealthcare
Kohler
New
Kohler KD1350
1.4 MW standby · Diesel · Liquid-cooled
1350 kW diesel industrial standby generator. Mid-range KD Series platform for data centers, healthcare, and large commercial applications.
Tier 23-phasedata-centerhealthcare
Kohler
New
Kohler 1250ROZMC
1.1 MW standby · Diesel · Liquid-cooled
1120 kW diesel 1500 RPM non-certified industrial generator powered by Mitsubishi. Mission-critical standby for data centers, hospitals, and large commercial facilities.
3-phasedata-centerhealthcare
Kohler
New
Kohler KD1000
1 MW standby · Diesel · Liquid-cooled
1000 kW diesel industrial standby generator. Megawatt-class KD Series unit for data centers, hospitals, and mission-critical infrastructure.
Tier 23-phasedata-centerhealthcare
Kohler
New
Kohler KD1500
1.5 MW standby · Diesel · Liquid-cooled
1500 kW diesel industrial standby generator. KD Series platform for data centers, healthcare, and mission-critical infrastructure.
Tier 23-phasedata-centerhealthcare
Need service or parts for the Kohler KD1250-4?
We service every major OEM and stock genuine parts for the most common models.
