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Generac GN-220 Engine

Name: Generac GN-220 Engine
Brand: Generac

The Generac GN-220 is a 0.22 L 1-cylinder air-cooled engine rated at 3600 rpm. It powers generator sets from Generac and Magnum, including the IMPACT-34 plus, Impact-36 plus, Impact-36G and NP-30G. It holds 0.95 L (0.3 gal) of oil.

Also known as: Generac GN-220, GN-220

0.22 L

Displacement

Cylinders

3600 rpm

Rated speed

0.95 L

Oil capacity

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

Engine specifications

Oil capacity	0.95 L
Displacement	0.22 L
Cylinders	1
Aspiration	air-cooled
Rated speed	3600 rpm

Generator sets powered by this engine

Shared across brands: Generac, Magnum

Generac IMPACT-34 plusGenerac Impact-36 plusGenerac Impact-36GGenerac NP-30GGenerac NP-40GMagnum MLT4000S

How to read your Generac engine serial & model number →

Common problems

Start/Stop switch at Stop, engine continues to run.
Cause: Defective Start/Stop switch
Fix: Replace switch.
Low Voltage Shutdown M04
High Temperature Shutdown M02
Engine starts, shuts down when Start/Stop switch is released.
Cause: Engine oil is low.
Fix: Check oil; add as needed.
Engine won't crank.
Cause: 15 amp fuse is blown.
Fix: Replace 15 amp fuse.
Engine cranks but won't start.
Cause: Out of fuel.
Fix: Replenish fuel.
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.

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

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter			0D3262	250 hr	Amazon eBay
Fuel filter			0D7515	400 hr	Amazon eBay
Oil filter			070185	100 hr	Amazon $28.95 eBay $30.00 FridayParts $45.99
Battery	Inspect battery posts and cables for tightness, corrosion; check battery fluid level, fill with distilled water only		—
Oil		24.0 oz	5W-30	25 hr	Amazon eBay $47.95
Spark plug	Champion RC12YC / AC R45S / Fram Autolite 65; gap 0.030 inch (0.76 mm)		072347	500 hr	Amazon $34.90 eBay $1.99

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 crankcase oil level	Check	8 hr		or before each use
Engine oil level	Check	8 hr		or before each use
Oil filter	Change	50 hr		First service — first filter change
Air cleaner paper filter	Clean	25 hr	12 mo	whichever comes first
Air cleaner paper filter	Replace	25 hr	12 mo	Replace if too dirty
Engine Oil and Oil Filter	Change	25 hr		First service — After the 25-hour break-in period
Foam Precleaner	Clean	25 hr	3 mo	Every three months or every 25 hours, whichever occurs first
Paper air filter	Clean	100 hr	12 mo	whichever comes first
Engine oil	Change	50 hr		First service — thereafter; more frequently under heavy load or high ambient temperatures
Engine oil filter	Replace	50 hr		First service — thereafter
Oil filter	Replace	50 hr		First service — thereafter
Spark Arrestor Screen	Inspect	50 hr	12 mo	Inspect and clean every 50 hours or once each year
Valve clearance	Adjust	50 hr		First service — after first 50 hours of operation
Air Intake	Clean	100 hr		At least once every 100 hours
Air Pre-filter	Clean	100 hr		100 Hours
Air intake screen	Clean	100 hr		clean more often if necessary
Engine Oil/Filter	Change	100 hr		100 Hours
Engine spark plug	Clean	100 hr		Clean or replace and set gap to 0.030 inch (0.76mm) every 100 hours
Fuel filter	Replace	400 hr	12 mo	whichever occurs first
Spark Plug	Adjust	100 hr		Clean and reset gap every 100 hours
Spark Plugs	Inspect	100 hr		100 Hours
Spark arrestor	Clean	100 hr		Inspect and clean spark arrestor
Spark arrestor muffler	Inspect	100 hr
Spark plug	Clean	100 hr		clean and set gap to 0.030 inch
Spark plug gap	Adjust	100 hr		Reset to 0.030 inch (0.76mm)
Paper Air Filter Element	Replace	250 hr		250 Hours
Spark Plugs	Replace	500 hr		500 Hours
Valve Lash	Adjust	500 hr		First service — 1st 50 Hours-then every 500 Hrs.
Battery	Test		6 mo	Every six months: check state of charge and condition
Battery state of charge	Test		6 mo	every six months, by automotive service facility
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	Clearance between exhaust system parts and combustible material	3 (76mm)	inch
Clearance	Clearance between fuel line and exhaust system parts	2	inch
Clearance	Clearance between generator and compartment walls/ceiling	1 (2 recommended)	inch	after metal lining and sound insulation installed
Clearance	Crankshaft end play (allowable)	0.006-0.023	inch (0.14-0.60mm)
Clearance	Exhaust system clearance to combustible material	3	inches (76mm)	minimum
Clearance	Exhaust system extension past outer edge of vehicle	1	inch (25mm)	minimum
Clearance	Fuel line clearance to exhaust system parts	2	inches	minimum
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	Throttle lever stop tab to stop block gap	0.003	inch (0.08-0.5mm)	engine coasting to a stop
Clearance	Throttle linkage gap between stop tab and stop block	0.003	inch (0.08-0.5mm)	minimum gap for throttle linkage adjustment
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 / 0.76mm)
Gap	Spark plug gap (metric)	0.76	mm
Gap	Throttle lever stop tab to carburetor stop block gap	0.003	inch (0.08-0.5mm)
Gap	Throttle linkage stop tab to stop block gap	0.003	inch
Other	Battery compartment ventilation opening	2	square inches at top
Other	Carburetor high altitude jetting	5000	feet	altitudes in excess of 5000 feet; consult Authorized Service Facility
Other	Engine crankcase and oil filter oil capacity	950 (1 quart)	ml
Other	Engine oil capacity	950	mL (1 quart)
Other	Exhaust system extension past outer edge of vehicle	1 (25mm)	inch
Other	Flexible fuel hose length	6	inches	at least 6 inches longer than needed
Other	Flexible fuel hose length	at least 6 inches longer than needed	inch
Other	Fuel pickup tube length (shared tank)	2 to 3 inches shorter than vehicle engine pickup tube	inch
Other	Generator compartment clearance around generator	1	inch (2 inches recommended)	all sides and ceiling
Other	Generator fuel pickup tube shorter than vehicle engine pickup tube	2 to 3	inches	recommended
Other	Generator mounting bolts	3/8"-16		four hardened steel bolts Grade 5; at least 3 threads visible past lock nuts when tight
Other	Generator restraint bolts	3/8"-16 hardened steel, Grade 5		at least 3 threads visible past retaining lock nuts
Other	Ignition timing	29 degrees BTDC (at higher speeds); 15-18 degrees BTDC at cranking speeds	degrees BTDC
Other	Maximum continuous cranking time	15	seconds	release start/stop switch if engine does not start
Other	Minimum acceptable Stator insulation resistance	rated volts/1000 + 1	megohm
Other	Minimum air inlet opening (unrestricted)	40	square inches	divide by free air inlet area percentage for restricted openings
Other	Minimum unrestricted cooling air inlet opening	40	square inches	divide by percentage free air inlet area to compensate for restrictions
Other	Oil filter tightening after gasket contacts adapter	3/4 to one	turn (by hand)
Other	Recommended minimum LP gas flow rate for air-cooled Impact-34 plus series generators	67	cubic feet per hour
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 fuel system leak test pressure	90	psi (620 kPa)	minimum; use soap and water or equivalent
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 gaseous fuel solenoid valve / secondary regulator	11	inches water column	optimum; 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	LP gas pressure at outlet of secondary regulator	1	inch water column (negative)
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
Pressure	Oil pressure switch	10	PSI	low oil pressure shutdown
Resistance	Fuel pump coil	0.75 to 1.00	ohm	nominal

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 10W-30	API Service Classification SF, SG or SH			10F to 100F; acceptable substitute for SAE 30 in summer
Engine oil	SAE 15W-40				Viscosity chart range 0F to 80F
Engine oil	SAE 30			950.0 ml	summer months; acceptable substitute SAE 10W-30
Engine oil	SAE 30 (summer); SAE 5W-30 (winter); SAE 10W-30 acceptable summer substitute			950.0 mL (1 quart)	Do not use SAE 10W-40. Use no special additives.
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 (summer); acceptable substitute SAE 10W-30 (summer)			950.0 ml (about 1 quart)	DO NOT USE SAE 10W-40
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			Winter months; -20F to 50F
Engine oil	SAE 5W30			950.0 ml	winter months; DO NOT USE SAE 10W-40
Engine oil	SAE 5W30 (winter)			950.0 ml (about 1 quart)
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 is an 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; 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 (propane/butane vapor withdrawal)				Impact-34 plus (LP unit); propane vaporizes to -20F(-29C), butane to 32F(0C)
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 gasoline (Leaded REGULAR grade acceptable substitute)	Not more than 10 percent ethanol if alcohol-containing; no methanol			High quality unleaded reduces lead and carbon deposits
Fuel	Unleaded gasoline (leaded regular acceptable substitute); no more than 10% ethanol; no methanol				Impact-36 plus (gasoline unit)
Fuel	Unleaded gasoline (leaded regular grade acceptable substitute)	Max 10% ethanol if alcohol present; no methanol			Unleaded reduces lead and carbon deposits; remove alcohol-containing gasoline during storage
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.
Fuel	high quality UNLEADED gasoline				Leaded REGULAR grade gasoline acceptable substitute; not more than 10 percent ethanol; no methanol
Fuel	LP gas (propane, butane or mixture)		above -29°C		Vapor withdrawal type system only. Propane vaporizes as low as -20°F (-29°C); butane returns to liquid below about 32°F (0°C).
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

Adjust Throttle Linkage adjustment

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

Tools: Pliers

Start generator, then shut it down right away.
Observe throttle lever rotating counterclockwise as engine coasts to stop.
Check gap of 0.003 inch (0.08-0.5mm) between stop tab and carburetor stop block.
With pliers, lightly compress the spring clip on the carburetor lever arm.
Slide linkage rod through clip and rotate throttle lever to set gap.
Release spring clip to secure adjustment.

Adjust Valve Clearance adjustment

Tools: Allen wrench, Feeler gauge, Crows foot

Engine at room temperature, piston at TDC of compression stroke.
Loosen the rocker arm jam nut.
Turn pivot ball stud with allen wrench while checking clearance with feeler gauge.
When clearance is correct, hold pivot ball stud and tighten jam nut with crows foot.
Tighten jam nut to 65-85 inch-pounds torque.
Recheck valve clearance to be sure it did not change.

Adjusting Throttle Linkage adjustment

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

Tools: Pliers

Start generator, then shut down right away; observe throttle lever rotate counterclockwise.
Check for gap of 0.003 inch (0.08-0.5mm) between stop tab and stop block.
With pliers, lightly compress spring clip on carburetor lever arm to slide linkage rod freely.
Rotate throttle lever to set gap to 0.003 inch (0.08-0.5mm).
Release spring clip to secure adjustment.

Adjusting Valve Clearance adjustment

Tools: allen wrench, feeler gauge, crows foot torque wrench

Position engine at room temperature with piston at TDC of compression stroke, both valves closed
Loosen rocker arm jam nut
Use allen wrench to turn pivot ball stud while checking clearance with feeler gauge to 0.001-0.003 inch
Hold pivot ball stud with allen wrench and tighten jam nut to 65-85 inch-pounds with crows foot
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 it will lose its clamping force

Tools: pliers

Start generator, then shut it down right away and observe throttle lever rotate counterclockwise as engine coasts to stop
Verify gap of 0.003 inch (0.08-0.5mm) between stop tab on throttle lever arm and stop block on carburetor die casting
With pliers, lightly compress spring clip on carburetor lever arm to allow linkage rod to slide freely
Rotate throttle lever to adjust gap to 0.003 inch clearance
Release spring clip to secure 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.

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
		DC output leads	+DC (Red), -DC (Blue), Return (Black), Ground (Green)	Route from generator DC output leads through approved flexible conduit to terminal block in DC junction box on inverter
		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
		Remote panel receptacle	Wire #0 (Ground), Wire #14 (Engine run signal), Wire #17 (Crank), Wire #18 (Stop)	Optional remote-mounted start/stop panel
12		Battery cables	Positive to large lug on starter contactor; Negative to frame ground	Cable size by length: 0-10 ft (0-3m): No.2; 11-15 ft (3.4-4.5m): 0; 16-20 ft (4.5-6m): 000. For warm weather use No.2 cable up to 20 feet.
120	Single	Leads BLACK to WHITE (line-to-neutral)	BLACK (hot), WHITE (grounded neutral), GREEN (ground)	Grounded neutral bonded to frame of engine-generator; protected by 30-amp circuit breaker (CB1); dual stator windings
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	AC output	T1 (Black), T2 (White), Green ground	From AC output junction box on inverter to double-pole double-throw transfer switch or approved isolation receptacle
120	single	Line T1 (black) hot; T2 (white) neutral; green ground	T1 (black), T2 (white), green (0)	T2 (white) neutral is internally connected to ground (grounded neutral system). T1 is protected by circuit breaker CB1.

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 GN-220?

The Generac GN-220 engine has an oil capacity of 0.95 liters.

What is the displacement of the Generac GN-220?

The Generac GN-220 has a displacement of 0.22 liters with 1 cylinders.

Which generators use the Generac GN-220 engine?

The Generac GN-220 powers 6 generator set(s), including Generac IMPACT-34 plus, Generac Impact-36 plus, Generac Impact-36G, Generac NP-30G, Generac NP-40G.

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

The Generac GN-220 oil change interval is every 25 hours.

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

A commonly reported issue on generators using the Generac GN-220 is: Start/Stop switch at Stop, engine continues to run.. Cause: Defective Start/Stop switch. Fix: Replace switch..