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Generac 9.0L Engine

The Generac 9.0L is a 8.9 L 8-cylinder naturally aspirated engine rated at 1800 rpm, producing up to 111.2 kW. It powers generator sets from Generac, including the MG 150 and SG080. It holds 9.5 L (2.5 gal) of oil and 5.5 L (1.5 gal) of coolant.

Also known as: 9.0 L, Generac 9.0L

Part of the Generac 9.0L engine family — 2 variants share parts & fitment.

8.9 L

Displacement

Cylinders

1800 rpm

Rated speed

111 kW

Gross power

On this pageSpecs Generator sets Maintenance FAQ Torque & specs Fluids Wiring

Engine specifications

Oil capacity	9.5 L
Coolant capacity	5.5 L
Displacement	8.9 L
Cylinders	8
Aspiration	Naturally Aspirated
Rated speed	1800 rpm
Gross power	111 kW

Generator sets powered by this engine

Generac MG 150 Generac SG080

How to read your Generac engine serial & model number →

Common problems

Unit will not start in AUTO with utility loss. NOT ACTIVATED
Fix: See activation section in installation manual.
Warning active. LOW BATTERY
Fix: Clear alarm. From MAIN menu on the control panel, navigate to BATTERY MENU. Contact an IASD if battery is GOOD. Replace battery if CHECK BATTERY is displayed.
Engine does not crank
Cause: Fuse blown
Fix: Replace 7.5 amp fuse in generator control panel. Correct short circuit condition if fuse blows again.
Unit consumes large amounts of oil
Cause: Engine over filled with oil
Fix: Adjust oil to correct level.
No transfer to standby after utility source failure
Cause: Faulty transfer switch coil
Fix: Contact an IASD.
Engine cranks but will not start
Cause: Out of LP fuel
Fix: Replenish LP fuel. Turn on fuel shutoff valve.
Unit shuts down during operation. HIGH TEMPERATURE
Fix: Inspect ventilation around intake, exhaust, and rear of generator. Contact an IASD if no obstruction is found.
Unit is set to OFF, but engine continues to run
Cause: Faulty keypad
Fix: Contact an IASD.
No AC output from generator
Cause: Main line circuit breaker (MLCB) (generator disconnect) is OFF (OPEN)
Fix: Set MLCB (generator disconnect) to ON (CLOSED).
Unit was running and shuts down, attempts to restart. RPM SENSE LOSS
Fix: Clear alarm and remove loads from generator. Put back in AUTO and restart. If problem returns, contact an IASD to investigate possible fuel issue.
Unit running in AUTO but no power in house.
Fix: Check MLCB (generator disconnect). Contact an IASD if MLCB is set to ON.
Open F2 15 amp fuse F2
Fix: Replace F2 15 amp fuse if fuse blows again. Contact an IASD.
Open F1 7.5 amp fuse F1
Fix: Replace F1 7.5 amp fuse if fuse blows again. Contact an IASD.
Engine starts hard and runs rough
Cause: Air cleaner plugged or damaged
Fix: Inspect/replace air cleaner.

Compiled from service & troubleshooting documentation across every generator set that uses the Generac 9.0L.

Maintenance schedule

Item	Capacity	Part #	Interval
Air filter		—	1000 hr
Fuel filter		—
Oil filter		—	1000 hr
Battery		—	1000 hr
Belt		—
Coolant	9.5 L	—
Coolant filter		—
Oil		—	200 hr
Spark plug		—	1000 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service specifications

Type	Item	Value	Unit	Condition
Other	Max Harmonics	3.50	%
Pressure	Maximum External Press Drop on Radiator	0.5	inches H2O

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

Fluid	Grade	Standard	Ambient	Capacity	Notes
Fuel	Natural Gas				950 BTU / Cu.Ft

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

Voltage	Phase	Connection	Leads	Notes
208		Parallel Wye Network
480		Series Wye Network

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Parts cataloged across the Generac 9.0L family

Part #	Description	Category
013001	Startup Delay Return Delay Util Loss Volts Util Pickup Volts Dealer Edit: 013002 Crank Pause Time Cooldown Time Warmup Time Run Hours Dealer Edit: 013003 Select Batt. Voltage Reset Maintenance Low Coolant Temp. Select Fuel Dealer Edit: 013004 Enable Theft Alarm Enable Dual Fuel I/O Ext. Config. Preheat Mode Preheat Time Select Wire Setting Dealer Edit: 013067 I/O Ext. 1 Digital Inputs Digital Outputs Dealer Edit: Low Oil Pressure Parameter Group Voltage Code Fuel Level Indicators Dealer Edit: 013006 AMF Mode 1/2 Wire Actuation Ground Fault Dealer Edit: 013007 Reset Controller Factory Reset Update ECU Firmware Save/Load Config. Dealer Edit: 013008	ECM / ECU
012616	Sample Label	Service part / kit
012672	A	Service part / kit
013000	Dealer Menu	Service part / kit
013009	Dealer Test: Perform Quiet Test Dealer Test: Gen. Volts A Gen. Volts B Gen. Volts C Dealer Calibrate: Gen. Amps A Gen. Amps B Gen. Amps C Dealer Calibrate: Util. Volt A Util. Volt B Util. Volt C	Service part / kit
013010	Dealer Test: Perform Quiet Test Dealer Test: Gen. Volts A Gen. Volts B Gen. Volts C Dealer Calibrate: Gen. Amps A Gen. Amps B Gen. Amps C Dealer Calibrate: Util. Volt A Util. Volt B Util. Volt C	Service part / kit
013011	Dealer Test: Perform Quiet Test Dealer Test: Gen. Volts A Gen. Volts B Gen. Volts C Dealer Calibrate: Gen. Amps A Gen. Amps B Gen. Amps C Dealer Calibrate: Util. Volt A Util. Volt B Util. Volt C	Service part / kit
013012	Dealer Test: Perform Quiet Test Dealer Test: Gen. Volts A Gen. Volts B Gen. Volts C Dealer Calibrate: Gen. Amps A Gen. Amps B Gen. Amps C Dealer Calibrate: Util. Volt A Util. Volt B Util. Volt C	Service part / kit
013013	Dealer Test: Perform Quiet Test Dealer Test: Gen. Volts A Gen. Volts B Gen. Volts C Dealer Calibrate: Gen. Amps A Gen. Amps B Gen. Amps C Dealer Calibrate: Util. Volt A Util. Volt B Util. Volt C	Service part / kit
013014	Status Command Gateway 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
013015	Alarm Log Run Log Maintenance Log General 04/19/21 88F 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
013016	Alarm Log Run Log Maintenance Log General 04/19/21 88F 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
013017	Alarm Log Run Log Maintenance Log General 04/19/21 88F 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
013018	Alarm Log Run Log Maintenance Log General 04/19/21 88F 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
013019	Alarm Log Run Log Maintenance Log General 04/19/21 88F 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
013020	Alarm Log Run Log Maintenance Log General 04/19/21 88F 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
013021	Alarm Log Run Log Maintenance Log General 04/19/21 88F 013016 01: 04/19/21 10:59pm Very Low Battery ECODE 2751 Alarm Log: 013017 01: 04/19/21 10:59pm Stopped With Alarm Run Log: 013018 01: No Log To Display Maintenance Log: 013019 Generator: NOT ACTIVATED Serial No: Run Hours xxx:xxh:m SERVICE UNIT General Info 013020 Battery Condition: CHECK BATTERY General Info 013021	Service part / kit
0G7172	Piercing probes (alternative)	Service part / kit
0J09460SRV	flexible pin leads	Service part / kit
A0000683522	Flexible pin leads for use with AMP connector plugs	Service part / kit

Parts cataloged across all variants of this engine family — verify the exact part fits your specific variant and serial number before ordering.

Common questions

What is the oil capacity of the Generac 9.0L?

The Generac 9.0L engine has an oil capacity of 9.5 liters.

What is the displacement of the Generac 9.0L?

The Generac 9.0L has a displacement of 8.9 liters with 8 cylinders.

Which generators use the Generac 9.0L engine?

The Generac 9.0L powers 2 generator set(s), including Generac MG 150, Generac SG080.

How often should you change the oil in the Generac 9.0L?

The Generac 9.0L oil change interval is every 200 hours.

What is a common problem with the Generac 9.0L engine?

A commonly reported issue on generators using the Generac 9.0L is: Unit will not start in AUTO with utility loss.. Fix: See activation section in installation manual..