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Generac Inline 4 Engine

The Generac Inline 4 is a 2.4 L 4-cylinder naturally aspirated engine rated at 3600 rpm. It powers generator sets from Generac, including the In Line 4, QT022, QT025 and QT027. It holds 5.25 L (1.4 gal) of oil and 2.5 L (0.7 gal) of coolant.

Also known as: Generac Inline 4

2.4 L

Displacement

Cylinders

3600 rpm

Rated speed

5.25 L

Oil capacity

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Fault codes Procedures Wiring

Engine specifications

Oil capacity	5.25 L
Coolant capacity	2.5 L
Displacement	2.4 L
Cylinders	4
Aspiration	Naturally Aspirated
Rated speed	3600 rpm

Generator sets powered by this engine

Generac In Line 4 Generac QT022 Generac QT025 Generac QT027

How to read your Generac engine serial & model number →

Common problems

Unit will not start in AUTO with utility loss
Cause: Start delay countdown
Fix: If the start up delay is greater than expected, contact servicing dealer to adjust from 2 to 1500 seconds.
Unit will not start in AUTO with utility loss. NOT ACTIVATED
Cause: Unit not activated
Fix: Refer to activation section in owners manual.
No transfer to standby after utility source failure
Cause: MLCB (generator disconnect) is OFF (OPEN)
Fix: Reset generator disconnect to ON (CLOSED).
Engine cranks but will not start
Cause: No fuel
Fix: Replenish fuel / turn on fuel valve.
Unit will not start in AUTO with utility loss — LED RED LOW OIL PRESSURE
Cause: Check LEDs / screen for alarms
Fix: Check oil level and add oil as needed. If oil level is correct, contact an IASD
Engine starts hard and runs rough
Cause: Air cleaner plugged or damaged
Fix: Check and clean air cleaner.
Unit consumes large amounts of oil
Cause: Excessive engine oil
Fix: Adjust oil to proper level.
Engine will not crank
Cause: Blown fuse
Fix: Correct short circuit condition by replacing 7.5 amp fuse in generator control panel. Contact an Independent Authorized Service Dealer (IASD) if fuse continues to blow.
Engine won’t crank.
Cause: 1. 15 amp fuse blown. 2. Loose or corroded or defective battery cables. 3. Defective starter contactor. 4. Defective starter motor. 5. Dead or Defective Battery. 6. 5 amp fuse blown.
Fix: 1. Replace fuse. 2. Tighten, clean or replace battery cables as necessary. 3. Replace contactor.* 4. Replace starter motor.* 5. Remove, change or replace battery. 6. Replace fuse.*
Engine cranks but won't start
Cause: 1. Out of fuel. 2. Fuel solenoid (FS) is defective 3. Open Wire #14A from Engine Control circuit board. 4. Spark plugs defective. 5. Door on tank not closed.
Fix: 1. Replenish fuel. 2. Replace solenoid.* 3. Reconnect wire. 4. Clean, regap or replace plugs. 5. Close door on tank.
Yellow LED illuminated in any state LOW BATTERY
Fix: Clear alarm. Check the battery using the control panel under the MAIN menu using the BATTERY MENU option. If it states battery is GOOD contact servicing dealer. If it states CHECK BATTERY replace the battery.
No AC output from generator
Cause: Main line circuit breaker (MLCB) (generator disconnect) is OFF (OPEN)
Fix: Reset generator disconnect to ON (CLOSED).
Engine starts hard, runs rough.
Cause: 1. Flame arrestor (air cleaner) plugged or damaged. 2. Plugged fuel line. 3. Defective spark plugs. 4. Fuel pressure incorrect.
Engine oil level is low.
Cause: 1. Engine starts then shuts down. AUTO/OFF/MANUAL Switch at OFF, engine continues to run
Yellow LED illuminated in any state — LED YELLOW LOW BATTERY
Cause: Check screen for additional information
Fix: Clear alarm. Using control panel, check battery by navigating to BATTERY MENU option from MAIN MENU. If battery condition displays GOOD, contact an IASD. If control panel displays CHECK BATTERY, replace battery

Compiled from service & troubleshooting documentation across every generator set that uses the Generac Inline 4.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter			—	500 hr
Fuel filter			—	50 hr
Oil filter			—	100 hr
Battery	Group 24F, 525CCA		—
Belt	inspect belts and hoses		—	500 hr
Coolant	Standard	2.5	—
Coolant filter			—
Oil		4.0	—	100 hr
Spark plug			—

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

Service intervals

Item	Action	Hours	Months	Notes
Oil level	Check	24 hr	1 mo	Monthly or 24 hours of continuous operation
Oil	Change	200 hr	24 mo	First service — After the first 25 hours of operation
Oil filter	Change	200 hr	24 mo	First service — After the first 25 hours of operation
Valve clearance	Check	400 hr		First service — After the first 25 hours of operation
Engine oil and filter	Replace	100 hr	12 mo	First service — After first 25 hours; then every 100 hours or 1 year. Cold weather (<4.4°C) or continuous hot (>29.4°C): every 100 hours or 1 year
Coolant Level and Hoses	Check	125 hr	12 mo	Schedule A; also daily if running continuously
Enclosure Louvers	Check	125 hr	12 mo	Schedule A; also daily if running continuously
Fuel Lines	Check	125 hr	12 mo	Schedule A; also daily if running continuously
Lubricating Oil Level and Drain Hose	Check	125 hr	12 mo	Schedule A; also daily if running continuously
Lubricating Oil and Oil Filter	Replace	125 hr	12 mo	First service — Schedule A
Radiator for Clogging	Check	125 hr	12 mo	Schedule A; also daily if running continuously
Aceite de motor y filtro de aceite	Change	200 hr	24 mo	First service — Programa de mantenimiento A
Batería (condición, nivel de electrolito y estado de carga)	Check	200 hr	24 mo	Programa de mantenimiento A
Battery condition	Check	200 hr	24 mo	Schedule A.
Battery condition and charge	Check	200 hr	24 mo	Schedule A maintenance
Complete Tune-Up	Other	200 hr	24 mo	Independent Authorized Dealer must perform; 2 years or 200 hours
Engine oil	Change	200 hr	24 mo	First service — Up to a 2 year/200 hour oil change interval.
Huile à moteur et filtre à huile	Change	200 hr	24 mo	First service — Calendrier A: tous les deux ans ou toutes les 200 heures. Changer l'huile et le filtre après les 25 premières heures. En conditions froides (moins de 4,4 °C/40 °F) ou fonctionnant en continu à plus de 29,4 °C/85 °F, changer annuellement ou toutes les 100 heures.
Óleo lubrificante e filtro de óleo	Change	200 hr	24 mo	First service — Trocar após as primeiras 25 horas; Programação A (2 anos ou 200 h); em clima frio (<4,4 °C) ou quente contínuo (>29,4 °C) anualmente ou 100 h
Aceite del motor y filtro de aceite	Replace	400 hr	48 mo	First service — Programa B: cada cuatro años o 400 horas.
Air cleaner	Clean	400 hr		Clean or replace as necessary; R = Replace as Necessary; 400 hours
Air filter	Replace	400 hr	48 mo	Schedule B maintenance
Battery condition, electrolyte level, and state of charge	Inspect	400 hr	48 mo	Schedule B
Bougies d'allumage	Clean	400 hr	48 mo	Nettoyer les bougies, vérifier l'écartement ou les remplacer. Calendrier A et Calendrier B.
Bujía(s)	Replace	400 hr	48 mo	Programa B: cada cuatro años o 400 horas.
Bujías	Replace	400 hr	48 mo	Programa B; limpiar, comprobar separación y sustituir
Engine air filter	Replace	400 hr	48 mo	Schedule B; emissions-critical maintenance
Engine oil and oil filter	Change	400 hr	48 mo	First service — Schedule B.
Engine oil and oil filter	Replace	400 hr	48 mo	First service — Schedule B
Filtre à air du moteur	Replace	400 hr	48 mo	Calendrier B: tous les quatre ans ou toutes les 400 heures.
Filtro de aire del motor	Replace	400 hr	48 mo	Programa de mantenimiento B
Filtro de ar do motor	Replace	400 hr	48 mo	Programação B (4 anos ou 400 h)
Folga da válvula	Adjust	400 hr	48 mo	First service — Inspecionar/ajustar após as primeiras 25 h e depois a cada 400 h; Programação B; exclui 14/18 kW com motor 816 cc
Jeu des soupapes	Adjust	400 hr		First service — Vérifier et régler après les 25 premières heures de fonctionnement, puis toutes les 400 heures.
Luz de válvulas	Adjust	400 hr	48 mo	First service — Programa B; inspeccionar/ajustar cada 400 horas
Sediment trap	Clean	400 hr	48 mo	Schedule B maintenance
Separación de la válvula	Adjust	400 hr	48 mo	First service — Programa B. Inspeccione y ajuste después de las primeras 25 horas y luego cada 400 horas. No necesario en unidades 14/18 kW con motor 816 cc.
Spark plug gap / spark plug	Clean	400 hr	48 mo	Schedule B; inspect gap and replace if necessary; emissions-critical maintenance
Spark plug(s)	Clean	400 hr	48 mo	Schedule B; inspect gap and replace if necessary
Spark plug(s)	Inspect	400 hr	48 mo	Schedule B maintenance; clean, inspect gap, replace if necessary

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

Service specifications

Type	Item	Value	Unit	Condition
Clearance	Belt deflection	3/8 - 5/8	in	22 Ibs (10 kgf) force midway between water pump and alternator pulleys
Clearance	Belt deflection	7.6 - 12.7	mm	22 Ibs (10 kgf) force midway between water pump and alternator pulleys
Gap	Folga da vela de ignição	0,020	pol
Gap	Folga da vela de ignição	0,040	pol
Gap	Folga da vela de ignição	0,508	mm
Gap	Folga da vela de ignição	1,02	mm
Gap	Separación de electrodos de bujía (11 kW)	0.030	in (0.76 mm)
Gap	Separación de electrodos de bujía (16/20/22 kW)	0.040	in (1.02 mm)
Gap	Separación de electrodos de bujía (9 kW)	0.020	in (0.508 mm)
Gap	Separación de las bujías	0.508	mm (0.020 pulg.)
Gap	Separación de las bujías	1.02	mm (0.040 pulg.)
Gap	Spark Plug Gap	0.030	in (0.76 mm)	11 kW (GTH-530)
Gap	Spark Plug Gap (1.5L engines, 25/30 kW)	0.9	mm
Gap	Spark Plug Gap (2.4L engines, 22/27/36/45 kW)	1.07-1.17	mm
Gap	Spark Plug Gap (32/38 kW and 60 kW)	0.71	mm
Gap	Spark plug gap	0.020	in (0.508 mm)
Gap	Spark plug gap	0.020 in (0.508 mm)	in (mm)
Gap	Spark plug gap	0.040	in (1.02 mm)
Gap	Spark plug gap	0.040 in (1.02 mm)	in (mm)
Gap	Spark plug gap	0.508	mm
Gap	Spark plug gap	0.76	mm (0.030 in)
Gap	Spark plug gap	1.02	mm (0.040 in)
Gap	Spark plug gap (10 kW)	0.020	in (0.508 mm)
Gap	Spark plug gap (11 kW)	0.030	in (0.76 mm)
Gap	Spark plug gap (14-24 kW)	0.040	in (1.02 mm)
Gap	Spark plug gap (14–24 kW)	0.040	in (1.02 mm)	cold
Gap	Spark plug gap (16/20/22 kW)	0.040	in (1.02 mm)
Gap	Spark plug gap (9 kW)	0.020	in (0.508 mm)
Gap	Écartement des électrodes des bougies d'allumage	0.508	mm (0,020 po)
Gap	Écartement des électrodes des bougies d'allumage	0.76	mm (0,030 po)
Gap	Écartement des électrodes des bougies d'allumage	1.02	mm (0,040 po)
Other	Cold Smart Start fixed temperature	20 F (-7 C)	F (C)	22-26 kW
Other	Cold Smart Start fixed temperature	50 F (10 C)	F (C)	10-20 kW
Other	Compression Ratio (1.5L)	11:1
Other	Compression Ratio (2.4L)	9.5:1
Other	Exercise time length (16-22 kW)	5	minutes
Other	Exercise time length (9-11 kW)	12	minutes
Other	Fusível do painel de controle	7,5	A
Other	Ordem de partida (10 kW)	15 s de arranque, 7 s de repouso, seguidos por quatro ciclos adicionais de 7 s de arranque e 7 s de repouso		cinco ciclos de manivela
Other	Ordem de partida (14 a 24 kW)	16 s de arranque, 7 s de repouso, 16 s de arranque, 7 s de repouso, seguidos por três ciclos adicionais de 7 s de arranque e 7 s de repouso		cinco ciclos de manivela
Other	Perda de potência do motor por altitude	3,5	% a cada 304,8 m (1.000 pés) acima do nível do mar
Other	Perda de potência do motor por temperatura	1	% a cada 6 °C (10 °F) acima de 15 °C (60 °F)
Other	Redução de classificação GN vs PL	10 a 20	%
Other	Retardo de calentamiento con Arranque inteligente en frío	30	segundos	temperatura ambiente por debajo de la temperatura fijada
Other	Retardo de calentamiento normal	6	segundos	temperatura ambiente en o sobre la temperatura fijada
Other	Steady State Regulation	+/- 0.25%
Other	Steady state regulation	± 0.25%	%
Other	Tamanho mínimo de tanque de PL ao converter de GN	946	L (250 gal)
Other	Utility failure detection threshold	65	% of nominal (for five consecutive seconds)
Other	Utility restoration threshold	80	% of nominal (for 15 consecutive seconds)
Other	Voltage regulation	± 1%	%
Pressure	Fuel pressure at regulator - LP	10-12	in water column (19-22 mm Hg)
Pressure	Fuel pressure at regulator - Natural Gas	3.5-7.0	in water column (9-13 mm Hg)
Pressure	Fuel pressure at regulator, LP gas	10-12 in water column (2.49-2.99 kPa)	in water column (kPa)
Pressure	Fuel pressure at regulator, NG	3.5-7.0 in water column (0.87-1.74 kPa)	in water column (kPa)
Pressure	Fuel pressure to regulator (LP)	10-12	in water column (19-22 mm Hg)	LP gas
Pressure	Fuel pressure to regulator (NG)	3.5-7.0	in water column (9-13 mm Hg)	natural gas
Pressure	Fuel pressure to regulator (natural gas)	3.5-7	inches water column (7-13 mm mercury)
Pressure	Fuel pressure to regulator, LP	10–12	in water column (2.49–2.99 kPa)
Pressure	Fuel pressure to regulator, LP gas	10–12	in water column (2.49–2.99 kPa)

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
Coolant	50/50 ethylene glycol	Generac 50/50 ethylene glycol type coolant		9.5 liters	Use demineralized or distilled water; do not use propylene glycol. Coolant mix 40-60% volume.
Engine oil	30 weight organic oil (factory fill)				Units run and tested at factory prior to shipping, no break-in required
Engine oil	5W-20	Generac proprietary 5W-20 Synthetic (after 30 hour break-in)		3.8 liters	Factory filled with 5W-20; 60 kW capacity 5.25 quarts (5 liters). Do not use special additives.
Engine oil	5W-20 (Generac proprietary)	API Service Class SJ, SL, or better		1.03 L	Oil capacity including filter. Use for continuous use after the 25 hour break-in period; specifically formulated for gaseous powered Generac generators. Do not use special additives. Change every year or 100 hours in cold weather (below 40 F) or continuous hot weather (above 85 F).
Engine oil	5W-30	Aceite orgánico 5W-30 (la unidad se entrega de fábrica llena con este aceite)			Compruebe el nivel de aceite y, de ser necesario, añada la cantidad apropiada con la viscosidad correcta. No llene en exceso. Consulte 'Recomendaciones para el aceite de motor' para tipo/viscosidad.
Engine oil	5W-30 (factory fill) / 5W-20 GEO (continuous)	Generac proprietary gaseous engine oil (GEO)			Unit comes filled with 5W-30 organic oil; after 25 hour break-in use 5W-20 GEO
Engine oil	SAE 5W-30 Synthetic	API Service Class SJ, SL or better			Do not use special additives
Engine oil	SAE 5W-30 sintético	API SJ, SL o mejor		1.03 l	9 kW; no usar aditivos especiales
Engine oil	SAE 5W-30 synthétique	API classe de service SJ, SL ou supérieure			Huile SAE 5W-30 synthétique pour toutes les plages de température. N'utilisez aucun additif spécial.
Engine oil	Synthetic 5W-30	API Service Class SJ, SL or better			For all temperature ranges; use no special additives
Engine oil	Synthetic SAE 5W-30	API Service Class SJ, SL, or better			Synthetic SAE 5W-30 for all temperature ranges. Do not use special additives. Capacities incl. filter: approx. 1.1 qt (1.03 L) 9 kW; approx. 1.7 qt (1.6 L) 11 kW; approx. 1.9 qt (1.8 L) 16/20/22 kW.
Engine oil	10W-30	API Service Class SJ, SL or better	-23°C to 4°C		Between 40 and -10 F (4 and -23 C)
Engine oil	SAE 30	API Service Class SJ, SL or better	above 0°C		Above 32 F (0 C)
Fuel		Gas natural: contenido de BTU de por lo menos 1000 BTU/ft3 (37,26 MJ/m3). Gas LP: por lo menos 2500 BTU/ft3 (93,15 MJ/m3)		250.0 gal (946 l)	Tamaño mínimo del tanque de LP es 250 gal (946 l), salvo que los cálculos de la unidad indiquen uno mayor. Solo sistema de extracción de vapor para LP.
Fuel	Gas natural	mínimo 1000 BTU por pie cúbico (37.26 megajulios por metro cúbico)			Reducciones típicas de gas natural 10-20 % respecto a LP
Fuel	Gaz naturel			37.26 mégajoules par mètre cube (1 000 BTU par pied cube) minimum	Teneur en BTU minimale du gaz naturel.
Fuel	Gaz naturel d'au moins 37,26 mégajoules par mètre cube (1 000 BTU par pied cube)	NFPA 54
Fuel	Gaz propane liquide (gazeux)			93.15 mégajoules par mètre cube (2 500 BTU par pied cube) minimum	Capacité de réservoir de gaz propane liquide minimum recommandée de 946 litres (250 gallons).
Fuel	Gaz propane liquide d'au moins 93,15 mégajoules par mètre cube (2 500 BTU par pied cube)	NFPA 58 / ICC IFGC			Réservoir de gaz propane liquide d'une capacité minimale de 946 litres (250 gallons).
Fuel	LP (vapor)	mínimo 2500 BTU por pie cúbico (93.15 megajulios por metro cúbico)		946.0 l	Se recomienda tanque de LP de 250 gal. (946 l) de tamaño mínimo si se convierte de NG a LP
Fuel	LP gas (vapor), minimum 2,500 BTUs per ft3 (93.15 megajoules per m3)				Vapor withdrawn liquid propane.
Fuel	Liquid Propane (LP) Vapor	btu content of at least 2,500 Btus per cubic foot (93.15 megajoules per cubic meter)		250.0 gallons (946 liters) minimum LP tank size recommended	If converting from natural gas to LP
Fuel	Liquid Propane (LP) vapor withdrawn or pipeline Natural Gas				NG min 1000 BTU/cu ft (37.26 MJ/m3); LP min 2500 BTU/cu ft (93.15 MJ/m3); min LP tank size 250 gal (946 L) recommended if converting from NG
Fuel	Liquid Propane (vapor)			2500.0 BTU/ft3 (93.15 MJ/m3) minimum	Vapor withdrawn; minimum tank size 250 gal (946 L) when converting from NG
Fuel	Liquid propane (LP) vapor	BTU content at least 2,500 BTUs per ft3 (93.15 megajoules per m3)			If converting to LP gas from NG, a minimum LP tank size of 250 gal (946 L) is recommended.
Fuel	Natural Gas	btu content of at least 1,000 Btus per cubic foot (37.26 megajoules per cubic meter)			Unit factory set for natural gas
Fuel	Natural Gas at least 1,000 BTUs per cubic foot; LPV at least 2,520 BTUs per cubic foot			250.0 gallons	Minimum LP tank size 250 gallons (946 liters) if converting to LPV from NG
Fuel	Natural gas (NG)	BTU content at least 1,000 BTUs per ft3 (37.26 megajoules per m3)			Unit factory-configured to run on NG.
Fuel	Natural gas (NG) or liquid propane (LP) vapor	Minimum 1,000 BTUs per ft3 (37.26 MJ per m3) for NG; minimum 2,500 BTUs per ft3 (93.15 MJ per m3) for LP			Dual fuel carburetion; factory configured for NG. If converting to LP, minimum LP tank size of 250 gal (946 L) recommended
Fuel	Natural gas (vapor) or liquid propane vapor	NG at least 1,000 BTU/ft3 (37.26 MJ/m3); LP at least 2,500 BTU/ft3 (93.15 MJ/m3)			Factory configured for NG; minimum 250 gal (946 L) LP tank recommended if converting to LP

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

Fault codes

Code	Name	Meaning	Severity	Action
AUXILIARY SHUTDOWN	Auxiliary Shutdown	Unit will not start	Shutdown	Set auxiliary shutdown switch(es) to CLOSED (I); clear alarm
BATTERY PROBLEM	Battery Problem	Yellow LED illuminated	Warning	Contact servicing dealer
Battery Problem	Battery Fault	Battery condition poor or battery charger issue	Warning	Inspect battery condition and connections. Contact IASD if needed.
CHARGER MISSING AC	Charger Missing AC	Yellow LED illuminated in any state	Warning	Contact an IASD
CHARGER WARNING	Charger Warning	Yellow LED illuminated	Warning	Contact servicing dealer
Controller Fault	Control Module Failure	Internal controller fault detected	Shutdown	Contact IASD for assistance
CONTROLLER FAULT	Controller Fault	Alarm message listed on controller menu.	Shutdown	Contact an IASD.
EMERGENCY STOP	Emergency Stop	Alarm message listed on controller menu.	Shutdown	Check emergency shutdown switch and reset.
FUSE PROBLEM	Fuse Problem	Unit will not start in AUTO with utility loss	Warning	Check 7.5amp fuse, replace with ATO 7.5Amp fuse if bad
HIGH TEMPERATURE	High Temperature	Unit shuts down during operation	Shutdown	Check ventilation around generator, intake, exhaust and rear of generator
High Temperature	Overheat	Engine operating temperature too high	Shutdown	Inspect ventilation around generator, intake, exhaust, and rear. Ensure no obstructions present.
INSPECT BATTERY	Inspeccionar batería	El LED amarillo se ilumina en cualquier estado	Warning	Inspeccionar la batería; pulsar ENTER para desactivar
LOW BATTERY	Low Battery	Yellow LED illuminated	Warning	Clear alarm; check battery via control panel BATTERY MENU; if GOOD contact dealer, else replace battery
Low Battery	Battery Voltage Low	Starting battery voltage below acceptable level	Warning	Inspect battery and battery cables. Charge or replace battery if necessary.
LOW OIL PRESSURE	Low Oil Pressure	Unit will not start in AUTO with utility loss	Shutdown	Check oil level / add oil per Owners Manual
Low Oil Pressure	Low Oil Level or Pressure	Insufficient oil pressure in engine	Shutdown	Check engine oil level and top up if necessary. Contact IASD if problem persists.
LOW VOLTS REMOVE LOAD	Low Volts Remove Load	Unit will not start in AUTO with utility loss	Shutdown	Clear alarm and remove household loads, put back in AUTO and restart
MISWIRE	Miswire	Unit will not start in AUTO with utility loss	Shutdown	Contact servicing dealer
NOT ACTIVATED	Not Activated	Unit will not start in AUTO with utility loss	Warning	Refer to activation section in owners manual
OVERCRANK	Overcrank	Unit will not start in AUTO with utility loss	Shutdown	Check fuel line shutoff valve ON, clear alarm, attempt manual start
Overcrank	Extended Cranking	Engine failing to start after extended crank attempts	Shutdown	Check fuel supply, spark plugs, and fuel system. Contact IASD for further diagnosis.
Overload	Overload Detected	Electrical load exceeds generator capacity	Shutdown	Remove household electrical loads from generator
OVERLOAD REMOVE LOAD	Overload Remove Load	Unit shuts down during operation	Shutdown	Clear alarm, remove household loads, put back in AUTO and restart
OVERLOAD WARNING	Aviso de sobrecarga	Aviso de sobrecarga.	Warning	Remova as cargas domésticas do gerador.
OVERSPEED	Overspeed	Unit will not start in AUTO with utility loss	Shutdown	Contact servicing dealer
Overspeed	RPM Overspeed	Engine running at excessive RPM	Shutdown	Contact IASD for assistance
OVERVOLTAGE	Overvoltage	Unit will not start in AUTO with utility loss	Shutdown	Contact servicing dealer
Overvoltage	Output Voltage High	Generator voltage exceeding nominal rating	Shutdown	Reduce electrical load and restart. Contact IASD if issue persists.
RPM SENSE LOSS	RPM Sense Loss	Unit was running and shuts down, attempts to restart	Shutdown	Clear alarm, remove household loads, put back in AUTO and restart; may be fuel issue, contact servicing dealer
RPM Sensor Loss	RPM Signal Loss	RPM sensor signal not detected	Shutdown	Contact IASD for assistance
SERVICE A	Service A	Yellow LED illuminated, maintenance due	Info	Perform SERVICE A maintenance, hit ENTER to clear
SERVICE B	Service B	Yellow LED illuminated, maintenance due	Info	Perform SERVICE B maintenance, hit ENTER to clear
SHUTDOWN SWITCH	Shutdown Switch	Unit will not start. Flashing red LED.	Shutdown	Check emergency shutdown switches. Set switch(es) to CLOSED (I). Clear alarm.
STEPPER OVERCURRENT	Stepper Overcurrent	Unit will not start in AUTO with utility loss	Shutdown	Contact servicing dealer
UNDERSPEED	Underspeed	Unit will not start in AUTO with utility loss	Shutdown	Contact servicing dealer
Underspeed	Engine Speed Too Low	Engine RPM below nominal specification	Shutdown	Contact IASD for assistance
UNDERVOLTAGE	Undervoltage	Unit will not start in AUTO with utility loss	Shutdown	Contact servicing dealer
Undervoltage	Output Voltage Low	Generator voltage below nominal rating	Shutdown	Reduce electrical load and restart. Contact IASD if issue persists.
USB WARNING	Aviso de USB	Aviso relacionado ao dispositivo USB.	Warning	Tente novamente com USB de melhor qualidade. Os nomes dos ficheiros no USB não podem ter mais de 8 caracteres.
Wiring Error	Electrical Wiring Fault	Wiring configuration error detected	Shutdown	Contact IASD for assistance
WIRING ERROR	Wiring Error	Unit will not start in AUTO with utility loss	Shutdown	Contact an IASD

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

Procedures

Adjust Valve Clearance adjustment

⚠ Allow engine to cool before adjusting valve clearance.

Tools: feeler gauge, 10 mm wrench, 13 mm wrench, 14 mm wrench, 8 mm wrench, 10 mm Allen wrench, torque wrench

Make sure piston is at TDC of compression stroke (both valves closed).
Remove spark plug wire(s) and position away from plugs.
Remove spark plug(s).
Remove the four screws attaching valve cover; remove and discard gasket.
Loosen rocker jam nut (10 mm wrench 9-11 kW; 13 mm wrench 16-22 kW).
Turn pivot ball stud (14 mm wrench 9 kW; 8 mm wrench 11 kW; 10 mm Allen 16-22 kW) while checking clearance with feeler gauge.
Hold rocker arm jam nut in place as pivot ball stud is turned.
When clearance correct, hold pivot ball stud and tighten rocker arm jam nut to torque spec.
Recheck valve clearance after tightening jam nut.
Install new valve cover gasket.
Install valve cover; tighten fasteners in cross pattern to torque spec.
Install spark plugs and torque to 18 ft-lbs (25 Nm).
Reattach spark plug wire to spark plug.
Repeat process for other cylinder if necessary.

Adjusting Valve Clearance adjustment

⚠ Risk of Burn. Allow the engine to cool before performing the following procedure.

Tools: Feeler gauge, 10 mm wrench, 13 mm wrench, 14 mm wrench, 10 mm hex key

Allow engine to cool before adjusting valve clearance.
Remove spark plug wire(s) away from plugs and remove spark plug(s).
Remove the four screws attaching the valve cover; remove and discard gasket.
Verify piston is at TDC of its compression stroke (both valves closed).
Loosen rocker jam nut using a 10 mm wrench (10 kW) or 13 mm wrench (20–22 kW).
Turn pivot ball stud with a 14 mm wrench (10 kW) or 10 mm hex key (20–22 kW) while checking clearance with a feeler gauge.
Hold pivot ball stud and tighten rocker arm jam nut to specification.
After tightening jam nut, verify valve clearance did not change.
Install new valve cover gasket and valve cover; tighten fasteners in a cross pattern.
Install spark plugs and tighten to 18 ft-lbs (25 Nm).
Attach spark plug wire to spark plug.
Repeat process for other cylinder if equipped.

Ajustar a folga das válvulas adjustment

⚠ Risco de queimaduras. Deixe o motor esfriar antes de executar o procedimento.

Tools: Chave de 10 mm, Chave de 13 mm, Chave de 14 mm, Chave sextavada de 10 mm, Calibrador

Remova os fios das velas de ignição e remova as velas de ignição.
Remova os quatro parafusos que prendem a tampa da válvula; descarte a junta.
Verifique se o pistão está no TDC do seu curso de compressão.
Solte a contraporca do balanceiro (C) com chave de 10 mm ou 13 mm.
Gire o pino de esfera articulada (D) com chave de 14 mm ou sextavada de 10 mm e ajuste a folga.
Aperte a contraporca do braço oscilante e inspecione a folga novamente.
Instale a nova junta e as tampas das válvulas; aperte em padrão transversal.
Instale as velas e aperte a 25 Nm; conecte os fios das velas.

Ajuste de la luz de válvulas adjustment

⚠ Dejar enfriar el motor antes de ajustar.

⚠ Iniciar los cuatro tornillos antes de apretar.

Tools: Calibre de espesores, Llaves de 8/10/13/14 mm, Llave de casquillo, Casquillo grande

Cerrar la válvula de combustible y desconectar la batería.
Retirar cable(s) de bujía y alejarlos.
Retirar la(s) bujía(s).
Llevar el pistón al PMS de la carrera de compresión.
Retirar los cuatro tornillos de la cubierta de válvulas y desechar la junta.
Aflojar la contratuerca del balancín.
Girar el prisionero de bola pivote para ajustar la luz con calibre.
Sostener el prisionero y apretar la contratuerca; verificar y reinstalar con junta nueva.

Ajuste de la separación de la válvula adjustment

⚠ Deje que el motor se enfríe antes del procedimiento.

⚠ Desconecte el cable negativo y luego el positivo de la batería.

⚠ No necesario en unidades 14 o 18 kW con motor de 816 cc.

Tools: Llave de 10 mm, Llave de 13 mm, Llave de 14 mm, Llave hexagonal de 10 mm, Galga de espesores

Retire los hilos de las bujías y las bujías.
Retire los cuatro tornillos de la cubierta de la válvula y deseche la junta.
Verifique que el pistón esté en el PMS de su carrera de compresión.
Suelte la contratuerca del balancín (llave 10 mm en 10 kW, 13 mm en 20 a 24 kW).
Gire el espárrago del pivote (llave 14 mm en 10 kW, hexagonal 10 mm en 20 a 24 kW) ajustando la separación.
Sostenga el espárrago y apriete la contratuerca del balancín.
Inspeccione la separación para verificar que no cambió.
Instale una junta nueva y la cubierta de la válvula; apriete en patrón cruzado.
Instale las bujías y apriete a 25 Nm (18 lb-pie).
Conecte los hilos de las bujías.

Check and Adjust Accessory / Drive Belt adjustment

Tools: Belt deflection gauge

Inspect belt for cracks, fraying, excessive wear or other damage.
Verify belt is free of grease and oil; replace if contaminated.
Using a suitable gauge, apply 22 Ibs (10 kgf) force midway between water pump and alternator pulleys.
Loosen DC alternator tension bracket screw.
Rotate alternator outward to reduce belt deflection.
Rotate inward to increase belt deflection.
Tighten DC alternator tension bracket screw to 17-22 ft-lbs (23-30 Nm).
Recheck belt deflection and repeat steps as necessary.

Checking Valve Clearance adjustment

⚠ Risk of Burn. Allow the engine to cool before performing the following procedure.

⚠ Accidental start-up. Disconnect spark plug wires when working on unit.

Tools: Feeler gauge, Large socket and socket wrench

Close fuel valve and disconnect battery to avoid accidental startup.
Remove spark plug wire(s) and position away from plug(s).
Remove spark plug(s).
Remove the four screws attaching the valve cover; remove and discard gasket.
Verify piston is at top dead center (TDC) of its compression stroke (both valves closed).
Inspect valve clearance between each rocker arm and valve stem with a feeler gauge.
Install replacement valve cover gasket(s).
Install valve cover(s); tighten fasteners in a cross pattern.

Conversion de carburant adjustment

⚠ Explosion et incendie. Le carburant et ses vapeurs sont extrêmement inflammables et explosifs.

Localiser le bouton orange de conversion (A).
Tourner le bouton vers la flèche indiquant la source de carburant jusqu'à l'arrêt.
Le bouton tourne sur 180° et glisse dans le corps du mélangeur pour le propane liquide.
Saisir la sélection du carburant (PL ou GN) sur l'automate de contrôle (Assistant d'installation ou menu EDIT > Fuel Selection).

Conversión de combustible adjustment

⚠ Explosiones e incendio: no se permiten fugas de combustible.

Ubique la perilla naranja de conversión de combustible (debajo del mezclador en 9 kW, sobre el mezclador en 11 kW–22 kW).
Gire la válvula hacia la marca de flecha de la fuente de combustible hasta que se detenga.
Introduzca la selección de combustible (LP/gas natural) en el controlador mediante el Asistente de instalación o el menú EDIT, 'Fuel Selection'.

Fuel Conversion Procedure from NG to LPV adjustment

⚠ Fuel conversion software is password protected

⚠ Failure to convert both hardware and software violates EPA regulations

Tools: Flat blade screwdriver, Pipe sealant

Turn off the main gas supply.
Remove battery negative cable (black) from battery negative (-) terminal.
Remove carburetor fuel hose from outlet port.
Remove screw at front of power wire connector and pull connector from fuel solenoid.
Expand spring clamp on fuel enrichment hose and remove from hose barb.
Remove black pipe assembly from outlet port; remove fuel solenoid assembly if clearance is insufficient.
Rotate NG fuel jet counterclockwise to remove from outlet port.
Rotate LP fuel jet counterclockwise to remove from jet keeper port.

Réglage du jeu des soupapes adjustment

⚠ Laisser le moteur refroidir avant d'ajuster le jeu des soupapes.

Tools: Clé à douille, Clés de 8/10/13/14 mm, Jauge d'épaisseur

Amener le piston au PMS de sa course de compression (les deux soupapes fermées).
Retirer les fils des bougies d'allumage et les écarter.
Retirer les bougies.
Retirer les quatre vis du couvercle des soupapes et jeter le joint.
Desserrer le contre-écrou du culbuteur (clé de 10 mm pour 9-11 kW ou 13 mm pour 16-22 kW).
Tourner le pivot à rotule tout en vérifiant le jeu avec une jauge d'épaisseur.
Maintenir le pivot et serrer le contre-écrou selon les spécifications.
Vérifier de nouveau le jeu.
Installer un nouveau joint sur le couvercle des soupapes.
Installer le couvercle et serrer les attaches en tracé croisé au couple spécifié.
Installer les bougies d'allumage et serrer à 25 N.m (18 pi-lb).
Rebrancher le câble de bougie.
Répéter au besoin pour l'autre cylindre.

Valve Lash Adjustment adjustment

⚠ Make sure the engine is at 60 to 80 F (16 to 27 C).

⚠ Hold the rocker arm jam nut in place as the pivot ball stud is turned.

⚠ Start all four screws before tightening.

Tools: 10 mm Allen wrench (530 cc engine), 13 mm Allen wrench (410, 990 and 999 cc engines), feeler gauge, socket wrench

Ensure engine is cool before checking; if clearance is 0.002-0.004 in (0.05-0.1 mm), adjustment is not needed.
Remove spark plug wires and position wires away from plugs; remove spark plugs.
Ensure piston is at Top Dead Center of its compression stroke (both valves closed).
Remove the four screws attaching the valve cover.
Loosen the rocker jam nut; turn the pivot ball stud while checking clearance with a feeler gauge.
Hold the pivot ball stud in place with the Allen wrench and tighten the rocker arm jam nut to 174 in-lb (19.68 N-m).
Recheck valve clearance to make sure it did not change.
Install new valve cover gasket and re-attach the valve cover.
Torque fasteners to 6-9 ft/lb (8-12 Nm).
Install spark plugs. Torque to 15-18 ft/lb (20-25 Nm).
Re-attach the spark plug wire to the spark plug.
Repeat the process for the other cylinder, if necessary.

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
		0 – c.c. (-)	NOIR no 3	Fil de mise à la terre normal; obligatoire si jumelé à un commutateur de transfert de gestion intelligente de l'alimentation de Generac.
		23	BLANCO Núm. 5	Cable de señal lógica del control de transferencia
		23 (White #5)	E	Transfer Control Signal Wire
		Generator control wiring - 1-115 ft (1-35 m)	N1, N2, T1, 23, 194	No. 18 AWG
		Generator control wiring - 116-185 ft (36-56 m)	N1, N2, T1, 23, 194	No. 16 AWG
		Generator control wiring - 186-295 ft (57-89 m)	N1, N2, T1, 23, 194	No. 14 AWG
		Generator control wiring - 296-460 ft (90-140 m)	N1, N2, T1, 23, 194	No. 12 AWG
		Longueur de fil 1 à 35 m (1 à 115 pi)	Calibre 18 AWG	Conducteurs en cuivre seulement.
		Longueur de fil 35 à 56 m (115 à 185 pi)	Calibre 16 AWG	Conducteurs en cuivre seulement.
		Longueur de fil 56 à 89 m (185 à 295 pi)	Calibre 14 AWG	Conducteurs en cuivre seulement.
		Longueur de fil 89 à 140 m (295 à 460 pi)	Calibre 12 AWG	Conducteurs en cuivre seulement.
		Neutral for battery charger	WHITE NEU/00	Must be connected to keep battery charged whether unit is running or not
0 VCC		0	NEGRO Núm. 3	CC (-) Cable común de conexión a tierra. Requerido si el generador está apareado con un interruptor de transferencia de gestión de alimentación inteligente Generac.
12 V c.c.		194 – c.c. (+)	ROUGE no 4	Pour les commandes de transfert.
12 VCC		194	ROJO núm. 4	CC (+) para los controles de transferencia
12 VDC		194 (Red #4)	D	DC (+) 12 VDC for Transfer Controls
12 VDC		DC (+) 12 VDC for transfer controls	RED 194
12 VDC		DC (-) common ground wire	BLACK 0
12 VDC		Transfer control signal wire	WHITE 23	Required if generator is paired with optional Digital Power Management (DPM) smart technology
120 V c.a.		T1	BLEU no 3	Avec fusible 120 V c.a. pour le chargeur de la batterie; doit être branché pour que la batterie demeure chargée.
120 VAC		Fused 120 VAC for battery charger	BLUE T1	Must be connected to keep battery charged whether unit is running or not
120 VAC		T1 (White #3)	B	Fused 120VAC for Battery Charger
120 VCA		T1	AZUL Núm. 3	Con fusible para el cargador de baterías (debe estar conectado para mantener la batería cargada, esté o no funcionando la unidad)
240 V c.a.		N1 et N2	JAUNE no 1 et no 2	Détectent les chutes et les hausses du réseau public.
240 VAC		N1 & N2 (Yellow #1 & #2)	A	Sensing for Utility Dropout and Pickup
240 VAC		Utility dropout and pickup sensing	YELLOW N1 & N2
240 VAC	1	Customer load to T1 and T2 terminals	T1, T2	Load leads are pre-wired at the factory
240 VAC	1	Generator (standby) source to E1 and E2 terminals	E1, E2
240 VAC	1	Utility (normal) source to N1 and N2 terminals	N1, N2	Single-phase neutral connected to neutral lug, not switched
240 VCA		N1 y N2	AMARILLO Núm. 1 y Núm. 2	Detección de desenganche y activación del servicio público

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 oil capacity of the Generac Inline 4?

The Generac Inline 4 engine has an oil capacity of 5.25 liters.

What is the displacement of the Generac Inline 4?

The Generac Inline 4 has a displacement of 2.4 liters with 4 cylinders.

Which generators use the Generac Inline 4 engine?

The Generac Inline 4 powers 4 generator set(s), including Generac In Line 4, Generac QT022, Generac QT025, Generac QT027.

How often should you change the oil in the Generac Inline 4?

The Generac Inline 4 oil change interval is every 100 hours.

What is a common problem with the Generac Inline 4 engine?

A commonly reported issue on generators using the Generac Inline 4 is: Unit will not start in AUTO with utility loss. Cause: Start delay countdown. Fix: If the start up delay is greater than expected, contact servicing dealer to adjust from 2 to 1500 seconds..