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Kohler 1250REOZM Generator Set

The Kohler 1250REOZM is a 1280 kW (1600 kVA) Diesel standby generator set powered by a Mitsubishi S12R-Y2PTAW-1 engine. It is available at 220/380 V, 240/416 V, 277/480 V, 347/600 V and 2400/4160 V, 3-phase and 60 Hz. It holds about 180 L (47.6 gal) of oil and 327 L (86.4 gal) of coolant, with a maximum ambient rating of 40 °C. Starting uses 4 batteries rated 1150 CCA at 12 V. The set measures 6353×2232×2490 mm (250.1×87.9×98.0 in). The same S12R-Y2PTAW-1 engine also powers generator sets from Generac and Igsa.

1280 kW
Standby
49.0 L
Displacement
180.0 L
Oil capacity
4
Document types

How to read your Kohler serial & model number →

Typical fuel consumption for 1280–1285 kW Diesel generators →

Compare with other 1280–1285 kW Diesel generators →

Service parts for the 1250REOZM

Grouped by system, with how many of each the parts manual calls for.

Fuel system

1 required
GM13947Fuel filter (secondary)$30.01Amazon

Oil system

1 required

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

FuelDiesel
Frequency60.0 Hz
Standby power1280 kW
Standby kVA1600
Prime power1160 kW
EmissionsTier 2 EPA-Certified for Stationary Emergency Applications
ControllerDecision-Maker 550, Decision-Maker 6000
Oil capacity180.0 L
Alternator7M4046, 7M4048, 7M4050, 7M4052, 7M4172, 7M4174, 7M4288, 7M4366, 7M4368
Voltage options220/380 V, 240/416 V, 277/480 V, 347/600 V, 2400/4160 V
Phase3
Power factor0.8
Battery cranking1150 CCA
Battery voltage12 V
Battery quantity4
Coolant capacity327 L
Max ambient40 °C
Dimensions (L×W×H)6353×2232×2490 mm

Engine

Mitsubishi S12R-Y2PTAW-1
Oil capacity150.0 L
Coolant capacity130.0 L
Displacement49.0 L
AspirationTurbocharged
Rated speed1800 rpm

Maintenance & consumables

for the Mitsubishi S12R-Y2PTAW-1
ItemSpecCapacityPart #Interval
Air filterDry180 hr
Fuel filterSecondaryGM13947 Amazon $30.01 eBay $79.99
Oil filterGM38852 Amazon $79.89 eBay
BatteryFour, 1150180 hr
BeltFlexible Disc180 hr
Spark plugN/A180 hr

Service specifications

30
TypeItemValueUnitCondition
Other10 in. weld flange bolt circle diameter B361.95mm (14.25 in.)
Other10 in. weld flange outside diameter C406.4mm (16.0 in.)
Other10 in. weld flange quantity of bolts / bolt hole diameter D12, 25.40mm (1.00 in.)
Other12 in. weld flange bolt circle diameter B431.80mm (17.00 in.)
Other12 in. weld flange outside diameter C482.6mm (19.0 in.)
Other12 in. weld flange quantity of bolts / bolt hole diameter D12, 25.40mm (1.00 in.)
Other14 in. weld flange bolt circle diameter B476.25mm (18.75 in.)
Other14 in. weld flange outside diameter C533.4mm (21.0 in.)
Other14 in. weld flange quantity of bolts / bolt hole diameter D12, 28.58mm (1.13 in.)
Other16 in. weld flange bolt circle diameter B539.75mm (21.25 in.)
Other16 in. weld flange outside diameter C596.9mm (23.5 in.)
Other16 in. weld flange quantity of bolts / bolt hole diameter D16, 28.58mm (1.13 in.)
Other18 in. weld flange bolt circle diameter B577.85mm (22.75 in.)
Other18 in. weld flange outside diameter C635.0mm (25.0 in.)
Other18 in. weld flange quantity of bolts / bolt hole diameter D16, 31.75mm (1.25 in.)
Other20 in. weld flange bolt circle diameter B635.00mm (25.00 in.)
Other20 in. weld flange outside diameter C698.5mm (27.5 in.)
Other20 in. weld flange quantity of bolts / bolt hole diameter D20, 31.75mm (1.25 in.)
Other5 in. weld flange bolt circle diameter B215.90mm (8.50 in.)
Other5 in. weld flange outside diameter C241.30mm (9.50 in.)
Other5 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
Other6 in. weld flange bolt circle diameter B254.0mm (10.0 in.)
Other6 in. weld flange outside diameter C279.4mm (11.0 in.)
Other6 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
Other8 in. weld flange bolt circle diameter B298.45mm (11.75 in.)
Other8 in. weld flange outside diameter C342.9mm (13.5 in.)
Other8 in. weld flange quantity of bolts / bolt hole diameter D8, 22.23mm (0.88 in.)
OtherWeld flange angle A (10, 12, 14 in. nominal pipe size)30deg.
OtherWeld flange angle A (16, 18, 20 in. nominal pipe size)22.5deg.
OtherWeld flange angle A (5, 6, 8 in. nominal pipe size)45deg.

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 power rating of the Kohler 1250REOZM?

The Kohler 1250REOZM is rated 1280 kW standby (1600.0 kVA).

What engine does the Kohler 1250REOZM use?

The Kohler 1250REOZM is powered by the Mitsubishi S12R-Y2PTAW-1 engine.

What kind of fuel does the Kohler 1250REOZM run on?

The Kohler 1250REOZM runs on Diesel.

What's the oil capacity on a Kohler 1250REOZM?

The Mitsubishi S12R-Y2PTAW-1 engine in the Kohler 1250REOZM has an oil capacity of 150.0 liters.

What alternator comes on the Kohler 1250REOZM?

The Kohler 1250REOZM uses a 7M4046, 7M4048, 7M4050, 7M4052, 7M4172, 7M4174, 7M4288, 7M4366, 7M4368 alternator.

Which oil filter part number does the Kohler 1250REOZM take?

The Kohler 1250REOZM uses oil filter part number GM38852.

Which fuel filter part number does the Kohler 1250REOZM take?

The Kohler 1250REOZM uses fuel filter part number GM13947.

Parts

34model family
Part #DescriptionQtySystem
GM13942Oil Filter4Oil filter Amazon $60.99 eBay $37.99
GM13943Oil Filter (bypass)1Oil filter Amazon eBay
GM13944Thermostat4Thermostat eBay
GM13945Thermostat Gasket2Gasket eBay
GM13946Tip assembly, nozzle12Injector eBay $80.25
GM13947Filter, fuel4Fuel filter Amazon $30.01 eBay $79.99
GM13948V-Belt (alternator)1Belt Amazon eBay
GM13950Oil Filter (bypass)1Oil filter Amazon $67.35 eBay $23.66
GM13951Fuel Filter2Fuel filter Amazon eBay
GM13952Fuel Filter4Fuel filter Amazon eBay
GM13953Thermostat2Thermostat Amazon eBay
GM14525V-Belt (set of 4)1Belt Amazon eBay $94.95
GM14526V-Belt (set of 4)1Belt Amazon eBay $39.80
GM15752V-Belt1Belt Amazon eBay
GM15753V-Belt (alternator)1Belt Amazon eBay
GM15765Thermostat Gasket1Gasket eBay
GM21122V-Belt1Belt Amazon eBay
GM21663Fuel Filter2Fuel filter Amazon eBay
GM21727Thermostat Gasket2Gasket eBay
GM21733Tip assembly, nozzle16Injector Amazon eBay $176.95
GM21917V-Belt (alternator)1Belt Amazon eBay
GM31390Thermostat4Thermostat eBay
GM31436Tip assembly, nozzle6Injector eBay
GM32057Oil Filter4Oil filter Amazon eBay $9.99
GM35977Tip assembly, nozzle12Injector eBay
GM38852Oil Filter2Oil filter Amazon $79.89 eBay
GM64645Exhaust fan1Service part / kit buy
GM64647Enclosure heater, 1-phase, 208 V1Service part / kit buy
GM64648Enclosure heater, 1-phase, 240 V1Service part / kit buy
GM64649Enclosure heater, 3-phase, 208 V1Service part / kit buy
GM64650Enclosure heater, 3-phase, 240 V1Service part / kit buy
GM65322Handle, door1Service part / kit buy
GM65323Support, heavy-duty1Service part / kit buy
GM65325Door, latched1Service 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
Prime25%105.027.6
Prime50%176.046.4
Prime75%259.068.4
Prime100%344.090.9
Standby25%110.029.2
Standby50%193.051.0
Standby75%284.075.1
Standby100%392.0103.4

Available documents

Spec sheet — Kohler-1250REOZMD (Kohler)Reference — 1250-2000REOZM REOZD G6119 (Kohler)Reference — G6-39 0918AZ (Kohler)Parts manual — pb137 (Kohler)Parts manual — pb98 (Kohler)Service manual — tp6057 (Kohler)Service manual — tp6289 (Kohler)
Full service, cheapest listings

Priced items from this model's own parts manual.

Fuel filter (secondary) GM13947$30.01
Oil filter GM38852$79.89
2 priced items$109.90