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Generac GN-190 / GN-220 Engine

Name: Generac GN-190 / GN-220 Engine
Brand: Generac

The Generac GN-190 / GN-220 is a 1-cylinder natural engine. It powers generator sets from Generac, including the NP-30G and NP-40G. It holds 0.85 L (0.2 gal) of oil.

Also known as: Generac GN-190 / GN-220

Part of the Generac GN-190 engine family — 4 variants share parts & fitment.

Cylinders

0.85 L

Oil capacity

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

Engine specifications

Oil capacity	0.85 L
Cylinders	1
Aspiration	Natural

Generator sets powered by this engine

Generac NP-30GGenerac NP-40G

How to read your Generac engine serial & model number →

Common problems

Low Voltage Shutdown M04
High Temperature Shutdown M02
Overspeed Shutdown M03
Fix: Do not attempt a manual adjustment to control engine speed.
Low Oil Pressure Shutdown M01
Fix: Check the engine oil level. If necessary, add oil to the FULL mark.
Stator windings are shorted to ground
Fix: The Stator should be cleaned and dried. The Insulation resistance tests should then be repeated. If, after cleaning and drying, the Stator again falls the test, replace the Stator assembly.
Overvoltage condition and speed control system cannot reduce output voltage
Cause: A. Carburetor linkage sticking with throttle stuck partly open.
Fix: A. Repair sticking throttle.
No AC voltage can be measured across Stator connections at the Battery Charge Rectifier (BCR)
Cause: An open circuit condition probably exists in Wire 66 (Brown), or Wire 77 (Brown).
Fix: Replace Stator Assembly
If the engine starts but the Stepper Motor does not move, and shutdown occurs after several seconds
Cause: Broken or shorted Power Supply winding (Wires PS1 and PS2). Broken or shorted Timing winding (Wires TIM1 and TIM2).
If the engine shuts down but speed did NOT exceed 4500 rpm
Cause: One of the main windings (Power Phase 1 or 2) is open. One of the main windings (Power Phase 1 or 2) is shorted to ground.
Engine starts, but the Stepper Motor does not move, and engine shuts down after several seconds
Cause: The CCG circuit board’s micro-controiler may not be operating.
Engine starts, but Stepper Motor does not move. The following symptoms occur: (1) engine appears to operate too slowly. (2) engine is not able to handle the load and unit operates at low AC output voltage. (3) after several seconds under load, AC output voltage is turned off (overload condition)
Cause: A failure of the circuit board’s Stepper Motor drive.
Engine starts, but Stepper Motor does not move. The engine accelerates uncontrollably and shuts down when engine speed exceeds 4500 rpm
Cause: A failure of the circuit board’s Stepper Motor drive.
Engine starts, accelerates, shuts down at 4500 rpm
Cause: A. Carburetor linkage sticking with throttle stuck open. b. Stepper Motor failed or seized. c. Stepper Motor wire connections broken or disconnected. d. Stepper Motor not properly connected.
Fix: A. Repair sticking throttle. b. Replace Stepper Motor. c. Reconnect or repair. d. Reconnect wires.
Engine speed and output voltage are erratic under constant load, but the AC output does not turn off intermittently
Cause: Erratic timing detection may have occurred (Timing winding, Wires TIM1, TIM2).
Engine can be started, but shuts down after several seconds
Cause: A timing detection failure may have occurred (Timing winding, Wires TIM1, TIM2).

Compiled from service & troubleshooting documentation across every generator set that uses the Generac GN-190 / GN-220.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	Paper element w/ foam precleaner; clean by tapping, replace if extremely dirty		—	25 hr
Fuel filter			—	100 hr
Oil filter			—	50 hr
Battery	12 VDC automotive storage battery; 70 amp-hours / 360 cold-cranking amperes above 32F (0C); 95 amp-hours / 450 cold-cranking amperes below 32F (0C)		—
Belt			—
Coolant			—
Oil		946.0 ml	—	50 hr
Spark plug	Champion RC12YC (or equivalent); gap 0.030 inch (0.76mm)		—	100 hr

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
Engine oil level	Check	8 hr		At least every eight hours of operation, or before each use. Fill to dipstick FULL mark only.
Air cleaner paper filter	Clean	25 hr	12 mo	or once each year, whichever comes first; replace if extremely dirty
Air cleaner paper filter	Replace	25 hr	12 mo	Every 25 hours or once each year, whichever comes first
Paper air filter	Clean	25 hr	12 mo	Once every 25 operating hours or once each year, whichever comes first; replace if too dirty
Engine oil	Change	50 hr		First service — Thereafter, every 50 operating hours
Oil filter	Change	50 hr		First service — Thereafter, every 50 operating hours
Oil filter	Replace	50 hr		First service — Replace after the first 8 hours of operation, then every 50 operating hours
Valve clearance	Adjust	50 hr		First service — After the first 50 hours of operation
Air intake screen	Clean	100 hr		Clean more often if necessary
Engine spark plug	Clean	100 hr		Clean or replace and set gap to 0.030 inch (0.76mm) every 100 hours
Fuel filter	Replace	100 hr	12 mo	or once each year, whichever occurs first
Spark arrestor	Clean	100 hr		Inspect and clean every 100 hours of operation; replace if torn, perforated or damaged
Spark plug	Clean	100 hr		Clean or replace and set gap to 0.030 inch (0.76mm)
Spark plug gap	Adjust	100 hr		Reset to 0.030 inch (0.76mm)
Battery	Test		6 mo	Every six months have state of charge and condition checked with a battery hydrometer
Battery state of charge and condition	Test		6 mo	Have checked with an automotive type battery hydrometer

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	Carburetor throttle lever stop tab to stop block gap	0.003	inch
Clearance	Crankshaft end play (allowable)	0.006-0.023	inch (0.14-0.60mm)
Clearance	Oil pump tip clearance	0.0000-0.0010 design / 0.004 wear limit	inch (0.000-0.025mm)	measured on shaft in oil sump
Clearance	Oil ring end gap	0.015-0.055 design / 0.062 wear limit	inch	ring pushed down 2.75 inch
Clearance	Piston ring-to-groove side clearance	0.0004-0.0014	inch (0.012-0.034mm)
Clearance	Second ring end gap	0.006-0.016 design / 0.024 wear limit	inch	ring pushed down 2.75 inch
Clearance	Top ring end gap	0.005-0.016 design / 0.024 wear limit	inch (0.15-0.40mm)	ring pushed down 2.75 inch (70mm)
Gap	Gap between throttle lever stop tab and carburetor stop block	0.003	inch (0.08-0.5mm)
Gap	Spark plug gap	0.030	inch (0.8mm)
Gap	Throttle lever stop tab to carburetor stop block gap	0.003	inch (0.08-0.5mm)
Gap	Throttle linkage gap between stop tab and stop block	0.003	inch (0.08-0.5mm)	throttle lever rotated counterclockwise as engine coasts to a stop
Gap	Throttle linkage stop tab to stop block gap	0.003	inch
Other	Carburetor high altitude jetting	5000	feet	altitudes in excess of 5000 feet; consult Authorized Service Facility
Other	Ignition timing	29 degrees BTDC (at higher speeds); 15-18 degrees BTDC at cranking speeds	degrees BTDC
Other	Minimum acceptable Stator insulation resistance	rated volts/1000 + 1	megohm
Other	Standard cylinder bore diameter	2.7560-2.7570 (GN-190) / 2.953-2.954 (GN-220)	inches
Other	Valve seat width	0.034-0.044 design / 0.064 wear limit	inch (0.87-1.13mm)	grind seats to 45 deg, 0.040 inch width
Pressure	Engine compression pressure	60 nominal / 55 minimum	psi	cold engine while cranking
Pressure	Engine compression pressure (while cranking, cold engine)	55	psi	minimum allowable
Pressure	Engine compression pressure (while cranking, cold engine)	60	psi	nominal
Pressure	Engine compression pressure, minimum allowable	55	psi	while cranking, cold engine
Pressure	Engine compression pressure, nominal	60	psi	while cranking, cold engine
Pressure	Fuel pump outlet pressure	2.0 to 3.5	psi	at zero delivery
Pressure	Fuel pump pressure at zero delivery	2.0 to 3.5	psi
Pressure	LP gas inlet pressure to lockoff solenoid / secondary regulator	11	inches water column
Pressure	LP gas inlet pressure to lockoff solenoid / secondary regulator	11 (do not exceed 14)	inches water column
Pressure	LP gas pressure at inlet to fuel lockoff solenoid and secondary regulator	11	inches of water column	optimum; do NOT exceed 14 inches water column
Pressure	Low oil pressure switch actuation	5	psi
Pressure	Low oil pressure switch set point	5	psi
Pressure	Oil pressure relief valve opening	30	psi (approx.)
Pressure	Oil pressure relief valve opening pressure	approximately 30	psi
Resistance	Fuel pump coil	0.75 to 1.00	ohm	nominal
Resistance	Fuel pump coil nominal resistance	0.75 to 1.00	ohm
Resistance	Genistor COM to G1/G2/G3/G4	20-60	Ohms
Resistance	Ignition coil primary	0.5 to 1.5	ohm
Resistance	Ignition coil primary resistance	0.5 to 1.5	ohms
Resistance	Ignition coil secondary	16,000-17,000	ohm
Resistance	Ignition coil secondary	16000-17000	ohm
Resistance	Ignition coil secondary resistance	16,000-17,000	ohms (16.0-17.0 k-Ohms)
Resistance	Minimum acceptable stator insulation resistance	(rated volts / 1000) + 1	megohms	e.g. 120 VAC rated = 1.12 megohms
Resistance	Stator Battery Charge Winding (66 to 55 / 77 to 55)	0.037-0.042	ohm
Resistance	Stator Power Phase Windings (AC1/AC2/SL1/SL2 to lead 11)	0.30 to 0.42	ohm
Resistance	Stator Power Supply Winding (PS1 to PS2)	0.35-0.44	ohm
Resistance	Stator Timing Winding (TIM1 to TIM2)	0.35-0.44	ohm
Resistance	Stator battery charge winding (lead 55 to 77)	0.037-0.042	ohm
Resistance	Stator battery charge windings (66 to 55; 77 to 55)	0.037-0.042	ohm
Resistance	Stator power phase windings (AC1, AC2, SL1, SL2 to lead 11)	0.30 to 0.42	ohm
Resistance	Stator power phase windings (Lead AC1/AC2/SL1/SL2 to 11)	0.30 to 0.42	ohm
Resistance	Stator power supply winding (PS1 to PS2)	0.35 to 0.44	ohm
Resistance	Stator timing winding (TIM1 to TIM2)	0.35 to 0.44	ohm
Resistance	Stepper motor winding (RED to ORANGE/YELLOW/BROWN/BLACK)	19-21	ohm
Resistance	Stepper motor winding resistance	19-21	ohms	RED pin to ORANGE/YELLOW/BROWN/BLACK pins
Resistance	Stepper motor windings (RED to ORANGE/YELLOW/BROWN/BLACK)	19-21	ohm
Speed	Engine operating speed (variable)	2520 to 4050	rpm	corresponds to stator output 336-540 Hz
Speed	Engine operating speed range	2300-3910	rpm	varies with load and load voltage
Speed	Engine overspeed shutdown	4500	rpm	shutdown occurs if speed exceeds
Speed	Engine speed range	approximately 2300-3910	rpm	depending on load and load voltage (NOTE 1)
Speed	Ignition timing	29	degrees BTDC
Speed	Ignition timing at cranking speeds	15-18	degrees BTDC	cranking
Speed	NP-30G engine speed at 0 A load (113-121 VAC)	2250-2800	rpm

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
Engine oil	SAE 30 (summer); SAE 5W30 (winter)	API service classification SF, SG or SH		950.0 ml	SAE 10W-30 acceptable summer substitute; DO NOT USE SAE 10W-40. Crankcase and oil filter capacity about 950ml or about 1 U.S. quart. Use no special additives.
Engine oil	SAE 30 (with filter change)			946.0 ml	Engine crankcase oil capacity with oil filter change is about 1 U.S. quart (946 ml)
Engine oil	SAE 30 summer (SAE 10W-30 acceptable substitute); SAE 5W30 winter	API service classification SF, SG or SH		950.0 ml	Crankcase and oil filter capacity about 950ml or about 1 U.S. quart; do not use SAE 10W-40; use no special additives
Engine oil	SAE 5W-20 or 5W-30	For Service SC, SD, SE, SF or SG	below 0°C		Winter months (below 32 F / 0 C); DO NOT USE SAE 10W-40
Engine oil	SAE 5W-20 or SAE 5W-30	For Service SC, SD, SE, SF or SG	below 0°C		Winter months (below 32 F / 0 C); do not use SAE 10W-40
Engine oil	SAE 5W-30	API service classification SF, SG or SH		950.0 ml	Winter months; DO NOT USE SAE 10W-40
Engine oil	SAE 30	For Service SC, SD, SE, SF or SG	above 0°C		Summer months (above 32 F / 0 C). SAE 10W-30 is an acceptable substitute. Do not use SAE 10W-40.
Engine oil	SAE 30 (SAE 10W-30 acceptable substitute)	For Service SC, SD, SE, SF or SG	above 0°C	946.0 ml	Summer months (above 32 F / 0 C); DO NOT USE SAE 10W-40; capacity with oil filter change about 1 U.S. quart (946ml); without oil filter change about 29 fluid ounces (850ml)
Fuel	Clean, fresh, UNLEADED regular grade gasoline; leaded Regular acceptable substitute				Do not use gasohol; if gasoline containing alcohol is used it must not contain more than 10% ethanol. DO NOT USE GASOLINE CONTAINING METHANOL. DO NOT MIX OIL WITH THE GASOLINE.
Fuel	High quality UNLEADED gasoline (leaded REGULAR grade acceptable substitute)				If gasoline contains alcohol it must not contain more than 10 percent ethanol; do NOT use gasoline containing methanol
Fuel	High quality unleaded gasoline; leaded regular grade acceptable substitute				If gasoline contains alcohol it must not contain more than 10 percent ethanol and must be removed from the tank during storage; do NOT use any gasoline containing methanol
Fuel	LP gas (vapor withdrawal only)				Gaseous fuel systems; generator requires at least 67 cubic feet of gas per hour
Fuel	Unleaded gasoline	Leaded REGULAR grade gasoline is an acceptable substitute; if gasoline contains alcohol it must not contain more than 10 percent ethanol; do NOT use any gasoline containing methanol
Fuel	Unleaded regular gasoline				Gasoline fuel systems; leaded regular acceptable substitute; gasohol not recommended (max 10 percent ethanol); do not use methanol; do not mix oil with gasoline
Fuel	Unleaded, regular grade gasoline				Leaded regular may be used if unleaded unavailable. Gasohol not recommended; if used max 10% ethanol. DO NOT use methanol. Do not mix oil with gasoline.
Other	LP gas (vapor withdrawal) or natural gas				Gaseous fuel system; generator requires at least 67 cubic feet of gas per hour
Other	LP gas or natural gas (gaseous fuel systems)				Generator requires at least 67 cubic feet of gas per hour; use only approved components

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

Procedures

Adjusting Valve Clearance adjustment

⚠ Engine should be at room temperature with piston at TDC of compression stroke

Tools: Allen wrench, Feeler gauge, Crows foot

Loosen the rocker arm jam nut.
Use an allen wrench to turn the pivot ball stud while checking clearance with a feeler gauge.
When clearance is correct, hold the pivot ball stud and tighten the rocker arm jam nut with a crows foot.
Tighten the jam nut to 65-85 inch-pounds torque.
Recheck valve clearance to make sure it did not change.

Carburetor Adjustment (Idle Jet) adjustment

⚠ Do NOT adjust the fuel-air mixture excessively lean; can result in engine damage.

Turn the idle jet inward (clockwise) until it just contacts its seat; do not force.
Turn the idle jet outward (counterclockwise) 1-1/8 turns.
Start engine and let it warm up about five minutes.
With engine at no-load, turn idle jet clockwise (leaner) until speed decreases or fluctuates.
Turn idle jet counterclockwise (richer) until speed decreases/fluctuates or black smoke appears.
Very slowly turn idle jet clockwise until speed just stabilizes or black smoke just stops.

Carburetor Idle Jet Adjustment adjustment

⚠ Do NOT adjust the fuel-air mixture excessively lean. An excessively lean mixture can result in engine damage.

Turn the idle jet inward (clockwise) until it just contacts its seat; DO NOT FORCE.
Turn the idle jet outward (counterclockwise) 1-1/8 turns to allow the engine to start and warm up.
Run the engine at no-load and turn the idle jet clockwise (leaner) until engine speed starts to decrease or fluctuate.
Turn the idle jet counterclockwise (richer) until speed decreases/fluctuates or black exhaust smoke appears.
Very slowly turn the idle jet clockwise (leaner) until engine speed just stabilizes or black smoke just stops.

Throttle Linkage Adjustment adjustment

⚠ Do not overbend the spring clip or the clip will lose its clamping force

Tools: Pliers

Start the generator, then shut it down right away and watch the throttle lever rotate counterclockwise.
There should be a gap of 0.003 inch (0.08-0.5mm) between the stop tab and the stop block.
With pliers lightly compress the spring clip so the linkage rod slides freely.
Rotate the throttle lever to increase or decrease the gap to 0.003 inch clearance.
Release spring clip to secure the adjustment.

Valve Clearance Adjustment adjustment

Tools: Allen wrench, feeler gauge, torque wrench, crow's foot

Rotate the crankshaft until the piston is at top dead center (TDC) of its compression stroke; both valves should be closed.
Loosen the rocker arm jam nut.
Use an Allen wrench to turn the pivot ball stud while checking clearance between rocker arm and valve stem with a feeler gauge.
When clearance is correct, hold the pivot ball stud with the Allen wrench while tightening the jam nut with a crow's foot.
Recheck the valve clearance after tightening the jam nut.

Spark Test (Ignition System) diagnostic

Tools: spark tester

Disconnect the high tension lead from the spark plug.
Attach the spark plug high tension lead to the spark tester terminal.
Connect the spark tester clamp to the engine cylinder head.
Crank the engine rapidly; the engine must be turning at 350 rpm or more.
If spark jumps the tester gap, the ignition system is operating satisfactorily.

Test All Stator Windings to Ground (Insulation Resistance) diagnostic

⚠ All Stator leads must be isolated from other components, especially circuit boards, before performing tests. The high voltages used in testing insulation resistance will damage electronic components.

Tools: Hi-Pot tester or Megohmmeter

Disconnect and isolate all Stator leads before starting tests.
Connect the ends of all Stator leads together; make sure none touch any terminal or part of the generator.
Connect one tester probe to the junction of all Stator leads and the other to a clean frame ground on the Stator.
Apply a voltage of 1000 volts for about 1 second.
If insulation resistance is low, clean and dry the Stator and repeat the test; if it fails again replace the Stator assembly.

Testing the Battery Charge Circuit diagnostic

Tools: VOM (volt-ohm-milliammeter)

Disconnect Wire 77 at the Battery Charge Rectifier (BCR).
Disconnect Stator output Wire 66 at the BCR.
Disconnect Wire 55.
Set a VOM to Rx1 and zero the meter.
Connect the VOM test leads across Wires 77 and 55, then across Wires 66 and 55; note both resistance readings.
With the unit running, measure AC voltage at the Wires 66 and 77 terminals; if no AC voltage, an open circuit exists in Wire 66 or 77.
With engine running, check for DC voltage between the BCR Wire 55 and frame ground; if AC was present but DC is not, the BCR is defective.

Testing the Fuel Lockoff Solenoid diagnostic

Tools: VOM (volt-ohm-milliammeter)

Set a VOM to read battery voltage (12 VDC).
Connect the VOM test leads across Wire 14 (Red) at the solenoid and a clean frame ground.
Set the fuel primer switch on the generator panel to its ON position.
The meter should indicate battery voltage and the solenoid should energize open.
If battery voltage is indicated but the solenoid does not energize, replace the lockoff solenoid.
If battery voltage is not indicated, a problem exists in the DC control system.

Testing the Genistor diagnostic

⚠ DO NOT attempt to test the Genistor until ALL leads have been disconnected. It MUST be completely disconnected from the circuit or all test results are invalid.

Tools: VOM (volt-ohm-milliammeter)

Disconnect all wires from the Genistor before testing.
Set a VOM to a resistance scale allowing 20-60 ohms to be read and zero the meter.
Connect one VOM lead to COM and the other to terminals G1, G2, G3 and G4 one at a time; each should read 20-60 ohms.
Set the VOM to Rx1; connect across COM terminal and the center screw; should read continuity.
Check continuity across each AC1, AC2, SL1 and SL2 screw to its terminal.
Set VOM to Rx10,000 or Rx1K; there should be no continuity (infinity) between any of the screws.
Replace the Genistor if it fails any of these tests.

Testing the Stator with a VOM diagnostic

⚠ All stator leads must be disconnected and isolated before testing.

Tools: Volt-Ohm-Milliammeter (VOM)

Disconnect stator power phase leads AC1, AC2, SL1, SL2 at the Genistor and lead 11 at the main circuit breaker.
Isolate all leads and ensure none touch the frame.
Set VOM to Rx1 scale and zero the meter.
Connect one test lead to lead 11; measure resistance to AC1, AC2, SL1 and SL2 individually.
To test short-to-ground, set VOM to Rx10,000 or Rx1K and measure each lead to clean frame ground (should read infinity).
Test for shorts between windings by measuring between pairs (PS1-AC1, AC1-77, AC1-TIM1, PS1-TIM1, PS1-77, TIM1-77).

Testing the Stepper Motor diagnostic

Tools: VOM (volt-ohm-milliammeter)

Unplug the Stepper Motor connector from its receptacle on the CCG circuit board.
Set a VOM to its Rx1 scale and zero the meter.
Connect one probe to the connector pin for the RED wire and the other probe to the ORANGE, YELLOW, BROWN and BLACK pins in turn; each should read 19-21 ohms.
To test for a shorted condition, set the VOM to Rx10,000 or Rx1K and zero the meter.
Connect one probe to the RED wire connector pin and the other to the Stepper Motor case; meter should read infinity.
Replace the Stepper Motor if it fails any part of the test.

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
		Battery Charge Rectifier (BCR)	66 (Brown)
		Battery Charge Rectifier BCR	77 (Brown)	Stator lead
		CCG Circuit Board (CCB)	PS1 (Brown)	Stator lead
		CCG Circuit Board (CONN4)	PS1 (Brown)	Pin 1 of CONN4 connector
		Engine Controller Board (J1 pin 1)	56	Delivers 12 VDC to Starter Contactor while cranking only
		Genistor (G)	SL2 (Brown)	Stator lead
		Grounding Terminal	55 (Black)	Stator lead
		Ignition Sensor	RED (+)	Battery voltage from Ignition Module to Ignition Sensor
		Lead 11 (Blue) connects to Main Circuit Breaker CB1	11 / Blue
		Lead 55 (Black) connects to Grounding Terminal	55 / Black
		Lead 66 (Brown) connects to Battery Charge Rectifier BCR	66 / Brown
		Lead 77 (Brown) connects to Battery Charge Rectifier BCR	77 / Brown
		Lead AC1 (Gray) connects to Genistor	AC1 / Gray
		Lead AC2 (Yellow) connects to Genistor	AC2 / Yellow
		Lead PS1 (Brown) connects to CCG Circuit Board (CCB)	PS1 / Brown
		Lead PS2 (Yellow) connects to CCG Circuit Board (CCB)	PS2 / Yellow
		Lead SL1 (Orange) connects to Genistor	SL1 / Orange
		Lead SL2 (Brown) connects to Genistor	SL2 / Brown
		Lead TIM1 (Orange) connects to CCG Circuit Board (CCB)	TIM1 / Orange
		Lead TIM2 (Gray) connects to CCG Circuit Board (CCB)	TIM2 / Gray
		Main Circuit Breaker (CB1)	11 (Blue)
		Main Circuit Breaker CB1	11 (Blue)	Stator lead
120	Single Phase	T1 (black) is hot; T2 (white) is neutral	T1 (black), T2 (white), green ground wire	Grounded neutral; lead T2 internally connected to ground. Line T1 protected against overload by the circuit breaker (CB1). Use T1-T2 for 120 volts, 1-phase, 60 Hz AC loads. Single voltage AC connection system.
120	Single Phase	T1 (black) line, T2 (white) neutral internally connected to ground	T1 (black), T2 (white), green ground wire	Single voltage AC connection system; grounded neutral. Line T1 protected by circuit breaker (CB1).
120	single phase	T1 (black) is hot; T2 (white) is the neutral load and internally connected to ground; green lead (0) connects to ground in the RV junction box	T1 (black), T2 (white), 0 (green)	Figure 1 - Connection for 120 Volts Only; grounded neutral; AC connection system protected by a circuit breaker

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 GN-190 family

Part #	Description	Category
78601	ELEMENT, AIR FILTER	air_filter
86311	FUEL FILTER	fuel_filter
78629	GASKET, BREATHER	gasket
78631	GASKET, CARBURETOR/SKIRT	gasket
87478	GASKET, OIL FILTER ADAPTOR	gasket
89096	GASKET, CRANK CASE FLANGE	gasket
89476	GASKET, EXHAUST	gasket
90051	GASKET, CARB/SPACER/HEAD	gasket
90536	GASKET, AIR CLEANER OUTLET	gasket
94643	GASKET, OIL DRAIN PLUG	gasket
96362	GASKET, ROCKER COVER	gasket
96459	GASKET, CARB/INLET/ADAPTOR	gasket
A8822	GASKET, CYLINDER HEAD	gasket
30340	1/4" FUEL LINE (8" LONG)	hose
82580D	3/16" CARBURETOR LINE (4" LONG)	hose
86710	HOSE, CARBURETOR INLET	hose
89062	HOSE, BREATHER	hose
70185	FILTER, OIL	oil_filter
52617	DRAIN PLUG, M12 x 1.75" LONG	other_service
65795	Battery Charge Rectifier	other_service
77604	HOUR METER	other_service
86275	GENISTOR, TRIAC MODULE	other_service
86711	MODULE, IGNITION	other_service
86714	SCREEN, OIL PICK-UP	other_service
86730	TUBE, EXHAUST OUTLET	other_service
86731A	ASSEMBLY, MUFFLER	other_service
89049B	COIL, IGNITION	other_service
89680	SPARK ARRESTOR	other_service
90145	30A Circuit Breaker (all units); 30A Circuit Breaker Q-70G	other_service
90881A	ASSEMBLY, CARBURETOR	other_service
92234	RV CONTROL BOARD	other_service
94468-A	Manual Part No. 94468-A	other_service
A961	FUSE, 7.5A. AGC	other_service
A9969	ASSEMBLY, PCB CCG	other_service
90475	FUEL PUMP	pump
81695	SEAL, OIL-CRANKSHAFT	seal
88156	SEAL VALVE-INTAKE	seal
89045	SEAL, WASHER EXH. PIPE	seal
89048	SEAL, OIL FILTER HOLE	seal
90071	O-RING, 1.062" I.D.	seal
90072	O-RING .562" I.D.	seal
60108	GASKET, OIL FILTER SUPPORT	sensor
77667	Oil Pressure Switch	sensor
86697	ASSEMBLY IGNITION SENSOR	sensor
94090	SWITCH-THERMAL, OIL TEMP.	sensor
72347	SPARK PLUG-CHAMPION R12YC	spark_plug

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 GN-190 / GN-220?

The Generac GN-190 / GN-220 engine has an oil capacity of 0.85 liters.

Which generators use the Generac GN-190 / GN-220 engine?

The Generac GN-190 / GN-220 powers 2 generator set(s), including Generac NP-30G, Generac NP-40G.

How often should you change the oil in the Generac GN-190 / GN-220?

The Generac GN-190 / GN-220 oil change interval is every 50 hours.

What is a common problem with the Generac GN-190 / GN-220 engine?

A commonly reported issue on generators using the Generac GN-190 / GN-220 is: Low Voltage Shutdown.